Router Security Router Bugs Flaws Hacks and Vulnerabilities Website by     
Michael Horowitz 
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NOTE: I gave a presentation on Defensive Computing at the HOPE conference (July 2022) that was based on my Defensive Computing Checklist website.

If you care about the security of your router, and you should, it is best to avoid consumer grade routers. On the whole, the software in these routers is buggy as heck. Below is what I base this opinion on.

This page documents the existence of bugs in routers. Starting April 2018, I also track routers in the news which details the exploitation of router flaws.

You may be thinking that all software is buggy, but router software is probably worse. One reason for this is your ISP, which may have configured the router/gateway in an insecure way, either on purpose, to allow spying, or out of laziness or incompetence. Another reason is cost: router software is developed as cheaply as possible.

BIG BUGS: A number of flaws stand out. The port 32764 issue from January 2014 and April 2014 for example. A router backdoor was exposed, then instead of being removed, was just better hidden. Another flaw not to be missed is the Misfortune Cookie from December 2014. Then, of course, there is WPS, the electronic equivalent of a "hack me" sign on your back. Other huge flaws involved UPnP being exposed to the Internet and file sharing on a USB port.

THE US GOVERNMENT: In January 2017, the FTC accused D-Link of leaving its routers and webcam devices vulnerable to hackers. A lawsuit alleged that D-Link "failed to take reasonable steps to protect their routers and IP cameras from widely known and reasonably foreseeable risks of unauthorized access." D-Link was also accused of misleading the public about the security of their devices. D-Link denied they did anything bad. More on the Router News page.

This page has bugs from 2022, 2021, 2020, 2019 and 2018. Older bugs, from 2017 through 2012, are available at the bottom of this page. To see all the bugs on one B_I_G web page (makes it easy to find all the issues for any one manufacturer) click this button ==>



At this point, you could not pay me to use a Cisco router

Critical flaws found in four Cisco SMB router ranges - for the second time this year
by Simon Sharwood of The Register   August 5, 2022
For the second time this year, Cisco small business routers have critical flaws. Three flaws this time. The buggy models are the RV160, RV260, RV340, and RV345 Series. All three bugs have the same underlying problem, the programmers that work for Cisco are lazy. Put another way, each flaw is due to insufficient input validation. Two of the bugs are critical and a remote bad guy who does not know any passwords can totally take over the routers. Patches are available but the safest approach is to switch router vendors.

DrayTek routers have a critical flaw

Critical RCE vulnerability impacts 29 models of DrayTek routers
by Bill Toulas of Bleeping Computer   August 4, 2022
This is the second critical security flaw in DrayTek routers that I am aware of. The bug is a Remote Code Execution flaw with a CVSS v3 severity score of 10 (out of 10). In other words, it is as bad as bad gets. Remote attackers can completely take over vulnerable routers. The flaw is a buffer overflow in the web-based management interface. The bug can be exploited both on the WAN/Internet side and on the LAN side. Bug fixes are available.

JULY 2022

Arris bugs show the company's true personality

Arris / Arris-variant DSL/Fiber router critical vulnerability exposure
by Derek Abdine   July 29, 2022
There are three different bugs in muhttpd software that runs the web administration portal. One of the bugs is critical, two are somewhat impractical to exploit. The buggy muhttpd software is used in both Arris router products and whitelabel/OEM products by other vendors. The bug has been confirmed in Arris router models NVG443, NVG599, NVG589, NVG510, as well as ISP-customized variants such as BGW210 and BGW320. Here is the bigger issue: "The complete list of affected products is unknown as Arris has declined to comment on the affected product list." Lesson learned, we don't want any products from Arris. The most severe vulnerability allows unauthenticated path traversal from the root of the file system as the root user. This exposes a whole host of sensitive information. The muhttpd software was patched in June 2022. Prior to that the last release of the software was in 2010. Arris is content to use software that had not been updated in 12 years. The path traversal bug appears to be present in the initial release of the muhttpd software in 2006. If the web portal is not available on the WAN side, the critical bug can not be exploited remotely. However, it can still be exploited on the LAN side. This is another reason for VLANs, as it lets us limited which devices can see the router on the LAN side. The Security Checklist page lists some other LAN side protections that block users/devices from getting at the router.

JUNE 2022

Throw away old Cisco small business routers

If you're using older, vulnerable Cisco small biz routers, throw them out
by Jessica Lyons Hardcastle of The Register   June 16, 2022
Cisco can not be shamed into fixing old buggy routers. A critical vulnerability exists in the web-based management interface of the Cisco RV110W, RV130, RV130W, and RV215W routers, These models went End of Life back in 2019. The bug is CVE-2022-20825 and it is due to insufficient user input validation of incoming HTTP packets. In other words, lazy programmers. In addition, there is a critical vulnerability in Cisco enterprise security appliances that could allow a remote bad guy to log in to the web management interface. This bug they will fix.

MAY 2022

Well, this is new

Two business-grade Netgear VPN routers have security vulnerabilities that can't be fixed
by Zeljka Zorz of Help Net Security   May 20, 2022
Quoting: "Netgear has admitted that multiple security vulnerabilities in its business-grade BR200 and BR500 VPN routers can't be fixed due to technical limitations outside of their control, and is offering users a free or discounted replacement router." Netgear does not offer details of the vulnerabilities, which were reported by Joel St. John of IncludeSecurity. To exploit the bug(s) the router administrator would have to be logged on to the router while they visited a malicious website. Advice about this has been on the home page of this website for years.

Paying lots of money does not get you security

Hackers are exploiting critical bug in Zyxel firewalls and VPNs
by Ionut Ilascu of BleepingComputer   May 15, 2022
Jake Baines of Rapid7 discovered a bug in assorted Zyxel devices. Fixes are available. The bug was serious enough that the NSA warned Zyxel customers to patch immediately. These devices are supposed to provide security. The bug is CVE-2022-30525 and the buggy devices are the USG FLEX series, the ATP series, and the USG20-VPN/USG20w-VPN. The bug lets bads guys inject arbitrary commands remotely without authentication. One thing bad guys can do with this is to set up a reverse shell. The bug was due to un-sanitized URI input (sound familiar?) being fed into the os.system method. Rapid7 reported that there are over 15,000 vulnerable devices online. Shadowserver found over 20,000 Zyxel firewall models on the Internet that are potentially affected by the bug.

APRIL 2022

Yet another buggy router

Security audit of the SKYWORTH GN542VF router – how to hack the admin panel password without leaving the web browser!
by Alexey Miloserdov   April 5, 2022
The router is somewhat unusual. Each one ships with a unique password. The password is displayed on the login web page, but only if you are on the LAN side, not when you login from the WAN side. When someone logs in with the correct password from the WAN side, the router shows an error message. Sounds good, at first. However, the password is always in the login page and it is only hidden using JavaScript that can be easily manipulated with developer tools built into the web browser. And, while it does display an error when someone logs in from the WAN side, it nonetheless logs the person in. The error message is a scam. I don't know what country or ISP uses this router.

MARCH 2022

You can't make this up - another Zyxel critical bug

Zyxel urges customers to patch critical firewall bypass vulnerability
by Charlie Osborne, of ZDNet   April 1, 2022
A critical vulnerability in Zyxel firewall software has just been fixed. Buggy devices include their USG, ZyWALL, USG FLEX, ATP, VPN and NSG. The company has fixed "products that are within their warranty and support period" and did not say anything about older devices that may also be vulnerable. The bug is due to "the lack of a proper access control mechanism". Words with no meaning. The bug lets a bad guy bypass authentication and obtain administrative access. In other words, it is as bad as bad gets. Bug is CVE-2022-0342.


Many Zyxel routers are buggy as heck

Multiple Critical Vulnerabilities in multiple Zyxel devices
by G. Hechenberger, S. Robertz, S. Viehböck and T. Weber of SEC Consult   February 15, 2022
"Multiple Zyxel devices are prone to different critical vulnerabilities resulting from insecure coding practices and insecure configuration." All told, SEC Consult found eight different types of bugs. The bugs included: multiple unauthenticated buffer overflows, two unauthenticated Local File Disclosures (which lets bad guys read all files), Unsafe Storage of Sensitive Data and a couple command injection flaws. Not enough? They also found that Zyxel fails to use OS level protection mechanisms like PIE, stack canaries and relocation read only. SEC Consult offered no workarounds (really?). They also failed to say which, if any of the bugs can be exploited from the WAN side as those are obviously more dangerous than bugs that are exploitable from the LAN side only. There are fixes for some, not all devices. Many devices will not be fixed as they are too old to bother with (EoL). Some other devices will get their bug fixes in September 2022. The timeline shows that Zyxel took over a year before they issued fixes. I am told that Zyxel consumer routers are popular in Europe, especially in the UK. The UK popularity stems from their use of BroadCom chipsets that provide a very stable VDSL2 connection over old copper wire that is prone to line noise.

Yet again, critical security flaws in Cisco routers

Cisco inferno: Networking giant reveals three 10/10 rated critical router bugs
by Simon Sharwood of The Register   February 4, 2022
Cisco reminds me of the Wizard of Oz. Seemingly great and powerful on the outside, but inside a dumpster fire of disgracefully buggy software. The buggy hardware this time are the RV160, RV260, RV340 and RV345 products. Cisco revealed that there are 15 bugs, but a handful are brutal - as bad as bad gets. Some of the bugs are fixed, but not all.


Here we go again, another bug in NetUSB affects many routers

Millions of Wi-Fi routers vulnerable to hacker attack — what you need to do
by Paul Wagenseil of Toms Guide   January 11, 2022
Consumer routers are buggy enough without also expecting them to share assorted devices plugged into their USB ports. Software that enables this sharing, NetUSB, was found to be buggy back in May 2015. NetUSB is used in many routers. Which ones? None of your business. Back in 2015, there were 26 router vendors thought to be using NetUSB. Sometimes NetUSB can be disabled via the router web interface, sometimes not. This bug is a buffer overflow and, fortunately, is hard to exploit. NetUSB opens port 20005 on the LAN side of the router. Perhaps most worrying is that some routers are double buggy and open port 20005 on the WAN/Internet side also. If so, the router can be sent commands directly, NetUSB does not do authentication. The creator of NetUSB, KCodes, was told of the buffer over-run on Sept. 9, 2021, and a patch was issued on Oct. 4th. Netgear routers, the D7800, R6400v2 and R6700v3 were patched on Dec. 20, 2021. Other vendors that license NetUSB, Edimax, D-Link, Tenda, TP-Link and Western Digital have done nothing. D-Link is looking into it. Great reason to avoid TP-Link.



Bugs in the Netgear Nighthawk RAX43

Netgear Nighthawk RAX43 Multiple Vulnerabilities
by Evan Grant, Jimi Sebree of Tenable   December 30, 2021
The bugs are in firmware version which was the latest as of December 28, 2021. This article is dated the 30th and Netgear claims to have released new firmware on the 29th. Just like the below group of bugs with the R6700, some of which were fixed in 90 days. What bugs did Netgear fix? None of your business. Not what you want in a router vendor. Like the R6700, this router also uses HTTP by default for its web interface, saves passwords in plain text, includes old buggy jQuery libraries, includes a vulnerable version of the minidlna service and has insufficient UART protection mechanisms. But, that's not all. Configuration backups are encrypted with a hard-coded password (RAX50w!a4udk). And two bugs can be combined. The first is a buffer overrun, the second, command injection. Together someone can perform remote tasks as root, without authentication. As with the Tenable report below, this one too, does not make it clear which, if any, bugs can be exploited from the WAN side and under what circumstances.

Bugs in the Nighthawk R6700 that Netgear handles poorly

Netgear leaves vulnerabilities unpatched in Nighthawk router
by Bill Toulas of Bleeping Computer   December 31, 2021
Cybersecurity company Tenable found six high-risk vulnerabilities in the latest firmware version ( for the Netgear Nighthawk R6700v3 router. They notified Netgear of the bugs on Sept 30, 2021 and by Dec 30th had heard nothing back from Netgear about any possible fixes. So, they went public with the details. Not what you want from your router vendor. The bugs could let an attacker on the LAN side take complete control of the router. The danger from the WAN side is not clear. One easily understood issue is that insecure HTTP is used by default on communications to/from the device’s web interface. Also, passwords are stored in plain text. In addition to the six bugs, Tenable also found instances of a common problem with routers - the firmware includes old software with known bugs. Specifically, they found several instances of jQuery libraries relying on version 1.4.2 and they found an old buggy version of the MiniDLNA server software. Taking a step back, hardware versions 1 and 2 of this router are too old to fix (End of Life is the official buzzword) so Tenable only examined hardware version 3. Interesting wrinkle, Netgear released a new firmware for this router pretty much at the same time as Tenable went public with the bugs. What did Netgear fix? None of your business. Not what you want from your router vendor.

Consumer routers prove my point, yet again

Nine WiFi routers used by millions were vulnerable to 226 flaws
by Bill Toulas of Bleeping Computer   December 2, 2021
This is not the first time an examination of multiple routers has found a huge number of bugs. In this case, nine routers yielded 226 bugs. All were current models running the latest firmware. The routers were from Asus, AVM, D-Link, Netgear, Edimax, TP-Link, Synology, and Linksys. The automated system used to find these bugs only looks for known flaws. The underlying issue is old software that is not upgraded when fixes are made. The TP-Link Archer AX6000 was the worst router, with 32 flaws. The Synology RT-2600ac, which I hated, had 30 bugs. The best router had 18 bugs. The research was done by IoT Inspector, in collaboration with German IT magazine CHIP. They also found a way to send malicious firmware to the D-Link DIR-X1560. Most of the reported bugs have been fixed. Not said, is whether the fixes were for the one tested model or for all similar models. No one ever dwells on that. Also, the fixes were not tested to insure they really fix the problems.

Netgear again

Thousands of Netgear Wi-Fi routers need to be patched now - here's how
by Paul Wagenseil of Toms Guide   December 3, 2021
I think Paul is re-using his headlines at this point :-) Not the biggest flaws in the world. What stands out to me is that the bugs were first disclosed to Netgear on May 3, 2021. Long time ago. Buggy devices include 35 different models of routers, Wi-Fi range extenders and combination modem-routers. The bugs were found by British security firm Immersive Labs.


If there was ever a case to be made about not using an ISP router, this is it

Six million Sky routers had serious security flaw
by Jane Wakefield of the BBC   November 19, 2021
Quoting: "About six million Sky routers had a significant software bug that could have allowed hackers to take over home networks ... The problem has been fixed - but researchers say it took Sky 18 months to address.". Sky is one of the biggest ISPs in the U.K. The bug was in four Sky Hub models and 2 Booster models. The problem was with DNS rebinding and a malicious web page, anywhere on the Internet, could exploit the flaw. Most of these routers shipped with a default password which is never good. Better routers make you pick a new password at first boot. Anyone who changed the password was safe. It is not clear to me, after reading the report, if changing the internal IP address of the router offers protection from this attack. Final insult: Sky would not maintain communication with the company that found and reported the flaw, Pen Test Partners.

Still more Netgear bugs

Netgear patches severe pre-auth RCE in 61 router and modem models
by Catalin Cimpanu of The Record   November 17, 2021
A bug with UPnP lets devices connected to the router hack the router without knowing the password. A LAN side device can get Remote Code Execution as root on a buggy router. Perhaps most importantly, this is the fifth major set of remote code execution bugs that Netgear has needed to patch this year. Other remote takeover bugs were found in March (by NCC Group), June (by Microsoft), September (by Polish security researcher Gynvael Coldwind) and also in September (by GRIMM). One defense, not mentioned in the article, is to limit the LAN side devices that can communicate with the router. This is always a good idea. On some of the buggy routers, the bug an not be exploited. Why not? The fix for an earlier bug broke the UPnP SUBSCRIBE and UNSUBSCRIBE functions. Netgear fixed the latest bug in some of their routers but old ones (EoL or End of Life) were not fixed.

Routers are sitting ducks for hackers

PWN2OWN Austin 2021
by Dustin Childs of Zero Day Initiative   November 1, 2021
Three routers were targeted at a recent hacking contest and they all were successfully hacked.

The Cisco RV340 router was successfully attacked three times from the WAN/Internet side and six times from the LAN side. A software cesspool, it is. In the very definition of irony, the web page for the RV340 says "Connect Your Network Safely and Securely" Ha.

  1. An attacker used a logic error to compromise the WAN interface
  2. An attacker used an impressive stack-based buffer overflow to get code execution on the WAN interface
  3. An attacker used a unique command injection bug to takeover the Cisco RV340 from the WAN interface
  4. An attacker used a three-bug exploit chain to hack the LAN interface
  5. An attacker used a four-bug exploit chain, including some known bugs to hack the LAN side
  6. An attacker used four bugs to exploit the Cisco RV340 router via the LAN interface
  7. An attacker used three unique bugs, including an authorization bypass and a command injection, to get code execution on the LAN interface
  8. An attacker used a three-bug chain, including an authorization bypass and a command injection, to take over the LAN interface
  9. An attacker leveraged 4 bugs on the LAN interface, but some of the bugs had been seen earlier in the conference.
The TP-Link AC1750 router was successfully hacked three times.
  1. An attacker used an Out-Of-Bounds (OOB) Read to get a root shell via the LAN interface
  2. Another attacker also used an OOB Read bug to take control of the router via the LAN interface
  3. An attacker exploited the LAN interface of the router using a known bug that has not yet been fixed
The Netgear Nighthawk R6700 v3 Smart WiFi Router (AC1750) was hacked seven times, once from the WAN side, six times from the LAN side. The home page for the R6700 brags about Speed, Wi-Fi range and Reliability. Nothing about security. So, better than Cisco.
  1. An attacker used an integer overflow to gain code execution on the LAN interface
  2. An attacker used an authorization bypass with a command injection bug to get code execution on the LAN side
  3. An attacker combined a heap overflow and a stack-based buffer overflow to gain code execution on the LAN interface
  4. An attacker used an uninitialized variable to get a root shell via the LAN interface
  5. An attacker used an improper certificate validation and a stack-based buffer overflow to compromise the router via the WAN interface
  6. A attacker two bugs to exploit the router, but the path traversal bug was only an N-day
  7. An attacker used a pair of bugs to execute code via the LAN interface


SonicWall has holes in its wall

SonicWall warns users to patch critical vulnerability as soon as possible
by Pieter Arntz of MalwareBytes   September 24, 2021
SonicWall specializes in securing networks but a critical bug makes them less secure. The bug is in the SMA 100 series of devices, specifically the SMA 100, 200, 210, 400, 410, and 500v. Details: "... the vulnerability is an improper access control ... [that] allows a remote unauthenticated attacker to bypass path traversal checks and delete an arbitrary file. Which, if the attacker knows what they are doing, can potentially result in a reboot to factory default settings. With the default settings in place the attacker can gain administrator privileges by using the factory default credentials." Patches are available. The patches also include fixes for two other less critical bugs, a local privilege escalation flaw, and a denial-of-service vulnerability.

Fixes available for buggy Netgear routers

Netgear fixes dangerous code execution bug in multiple routers
by Sergiu Gatlan of Bleeping Computer   September 21, 2021
Adam Nichols of GRIMM discovered a bug in the Circle parental control service on these Netgear routers: R6400, R6700, R6900, R7850, R7900, R8000 and RS400. If you have a Netgear router, beware of their marketing. Paul Wagenseil warns "Because Netgear markets its home routers using somewhat misleading terminology - for example, the R7000 is also labeled as the 'Nighthawk AC1900 Smart WiFi Dual Band Gigabit Router' - you might want to flip your router over and check the sticker on the bottom for the real model name." If the Circle software is installed, the router is vulnerable. The bug is in the Circle update routine which runs as root. Wagenseil offers perspective on this: "The problem is in the Disney-designed Circle parental-control feature, which was rolled out to Netgear Nighthawk and Orbi mesh routers in 2017. The Orbis and newer Wi-Fi 6 Nighthawks got parental-control software built in-house by Netgear earlier this year, while the Circle service was discontinued for older Nighthawk models in late 2020." Updated firmware is available, but there are many steps to the manual update process. The bug is relatively hard to exploit as the bad guy must be must be able to intercept and modify the router's network traffic. Gatlan points out that earlier this month, Netgear fixed three severe security vulnerabilities impacting over a dozen of their smart switches, allowing bad guys to take over unpatched devices.

For two years, Virgin Media fails to fix a router bug

VPN users unmasked by zero-day vulnerability in Virgin Media routers
by Adam Bannister of Port Swigger   September 20, 2021
Fidus Information Security, a UK penetration testing consultancy discovered a flaw in the Virgin Media Super Hub 3 router and reported it in October 2019. In February 2020 Fidus was asked not to publicly reveal the flaw until the first quarter of 2021. They agreed. Suckers. Virgin Media, and parent company Liberty Global, both stopped responding to Fidus. As of the end of September 2021, the bug is still not fixed. The flaw is that the router will reveal the public IP address to anyone on the LAN side that knows how to ask for it. To exploit this, Fidus uses DNS rebinding along with a malicious DNS server for a malicious domain. Load a web page from that domain, and it can reveal the public IP address even when a VPN is being used. Not all VPNs, but many. Some do not allow access to LAN side devices, some do. A good VPN will offer a choice as there is no one right answer. The tested router is really the ARRIS TG2492 and Fidus believes the vulnerability probably works against all related models. Don't hold your breath for a comment from Arris.

One TP-Link router is buggy as heck. What about others?

"Amazon’s Choice" best-selling TP-Link router ships with vulnerable firmware
by Edvardas Mikalauskas of   September 2, 2021
The bugs in this one router model are not important. What is important is that, no doubt, many other TP-Link routers share these bugs and only this one model will be fixed. TP-Link is hugely popular, the article reports they sell over 150 million devices annually. The article is about the TP-Link AC1200 Archer C50 (v6) router. On Amazon it is rated 4.5 stars (out of 5) with over 61,000 ratings. Just shows how security is not a concern. The article covers many bases. For one: "The router is shipped with outdated firmware that is vulnerable to dozens of known security flaws". Then too: "The default version of the router's web interface app suffers from multiple bad security practices and vulnerabilities, including clickjacking, charset mismatch, cookie slack, private IP disclosures, weak HTTPS encryption, and more." They list 13 different issues with the web interface which is surely shared by many TP-Link routers. There were other security problems too. As for known bugs in the shipping firmware, some of these are fixed in later versions of the firmware, however the router does not auto-update. The researchers said that TP-Link responded quickly and plans on force-feeding the router a firmware update. As for the rest of the many TP-Link routers, this was not discussed. Par for the course.


How low can Cisco go? Pretty low.

Cisco says it will not release software update for critical 0-day in EOL VPN routers
by Jonathan Greig of ZDNet   August 27, 2021
Cisco to their customers: Yeah, it's a bug, but we are not going to bother fixing it because the routers are old. Go buy a new router.
Yet again, Cisco has been caught failing to validate input. Lazy, lazy, lazy. Again, again, again. This vulnerability is in the Universal Plug-and-Play (UPnP) service in their Small Business RV110W, RV130, RV130W, and RV215W routers. An unauthenticated attacker can execute arbitrary code or cause a vulnerable device to restart unexpectedly. The support page for the RV215W router says that the end of support date is November 30, 2024. Seems like they lied. And the links for EOL of the RV215W go here which says nothing at all about the RV215W. Cisco is really bad news.

More bugs that will never be fixed

Remote code execution flaws lurk in countless routers, IoT gear, cameras using Realtek Wi-Fi module SDKs
by Thomas Claburn of The Register   August 16, 2021
There are vulnerabilities in three Realtek SDKs accompanying its Wi-Fi modules. This article says there are 4 bugs, the original report lists a dozen. The hardware is used in almost 200 products made by more than 65 vendors. Vendors selling the buggy hardware include: AsusTEK, Amped Wireless, Belkin, Buffalo, D-Link (many devices), Edimax, EnGenius, Huawei, Logitech, Netis, Technicolor, Tenda, TRENDnet, Zyxel and Netgear. The flaws require an attacker to be on the same network as the vulnerable device, or be able to reach it over the Internet. It is not clear if a VLAN offers any protection. Remote unauthenticated attackers (the worst kind) can fully compromise a device and execute code with the highest level of privilege. One buggy device, the Realtek RTL819xD module, creates wireless access points. One estimate is that almost a million vulnerable devices may use the buggy software, including VoIP and wireless routers, repeaters, IP cameras, and smart lighting controls. Realtek will fix some of the bugs, others are in software that is too old to bother with. However, it is expected that most vulnerable devices will never be patched.

Fortinet falls down

Fortinet delays patching zero-day allowing remote server takeover
by Sergiu Gatlan of Bleeping Computer   August 17, 2021
This is interesting, to me, not because of the delay in patching that is the focus of the article. Instead, I take note the long list of security bugs in Fortinet software that is cited at the end of the article. It's pretty long. And, the fact that Fortinet clammed up and stopped responding to Rapid7 which found the latest bug. That is not acceptable.

Cisco bugs never cease. They are as inevitable as death and taxes

Cisco fixes critical, high severity pre-auth flaws in VPN routers
by Sergiu Gatlan of Bleeping Computer   August 4, 2021
The web-based interface of these Cisco routers are buggy: RV340, RV340W, RV345, RV345P (Dual WAN Gigabit VPN routers), RV160, RV160W, RV260, RV260P, and RV260W (VPN routers). Yet again, the underlying problem is improperly validated HTTP requests and insufficient user input validation. Yet again. If remote access is disabled, then buggy devices are safe on the WAN side. There is no protection at all on the LAN side (the web interface can not be disabled), so the existing patches should be installed ASAP. There are two bugs. Attackers without the password can trigger a denial of service condition or execute commands and arbitrary code.

Yet another widespread router flaw

Decade-long vulnerability in multiple routers could allow network compromise
by Jessica Haworth of Port Swigger   August 4, 2021
Evan Grant of Tenable discovered an authentication bypass vulnerability in many routers and modem/routers manufactured by Arcadyan. The bug exists in at least 20 router models from 17 different vendors including Asus, Verizon, Vodafone, British Telecom, O2 (Telefonica), Orange, Hughesnet, Deutsche Telekom, Telstra and Telus. Was your router made by Arcadyan? None of the articles mentioned how you can tell. I have recent photos of a Verizon FIOS G3100 router and it certainly does not say Arcadyan anywhere on the outside. The important lesson here for consumer routers is that the vendor selling you the device is not necessarily the one who manufactured it. Grant also found two separate flaws in some Buffalo routers. This was the first time Grant had looked at a router for bugs and he said the flaws were "fairly easy to discover" and "trivial to exploit" The widespread bug is a path traversal flaw and is assigned CVE-2021–20090. The bug has been around for at least 12 years and can be exploited by unauthenticated, remote attackers. What is not said is whether the flaw can be exploited on routers that have Remote Administration turned off. My guess is no and that this fact was left out to make the bug seem more important. That said, I recently used a Verizon FIOS G3100 router and the user interface for Remote Administration was so miserably confusing I could not tell if I was turning it on or off.
UPDATE: Aug 25, 2021. I am told by a Verizon FIOS customer that there is new firmware, version, for the G3100 Router. The router self-updates. According to Joshua Lowcock it only self-updates, but he documented a work-around to force an update. What changes are in this new release? None of your business, Verizon does not seem to keep a change log. However, the GUI for the Admin interface has changed dramatically, which can only be a good thing. Lowcock notes that the new firmware has a dedicated wireless network for IoT, offers control over each wifi antenna and has a new performance-mode tri-band setting. Nothing about a security bug fix. Way back when, Verizon kept using WEP a decade after it was known to be insecure, so I would not get my hopes up about bug fixes.

JULY 2021

Bugs in a D-Link router. Just one model? None of your business

D-Link issues hotfix for hard-coded password router vulnerabilities.
by Sergiu Gatlan of Bleeping Computer   July 16, 2021
If hard code password backdoors do not turn you off D-Link, nothing will. A guy at Cisco, Dave McDaniel, took a look at the DIR-3040 router and found it to be a security nightmare. Multiple vulnerabilities: command injection, information disclosure and the biggie - executing arbitrary code. I am not surprised. I am also not surprised that the original report from Cisco and the article about it from Bleeping Computer focus exclusively on the DIR-3040. So too does D-Link. This is disgraceful. What about other similar routers with similar firmware? Clearly, that is none of our business. What should someone with a DIR-2640 or DIR-1950 do? Router vendors share firmware across multiple models. It is all but guaranteed that similar models have the same bugs. Anyone using a D-Link router clearly does not care about security. Still, Cisco says the bugs were fixed on July 13th but D-Link says on June 9th. Beats me.

A bad Summer for SonicWall

Another Brick in the Wall: eCrime Groups Leverage SonicWall VPN Vulnerability
by Heather Smith and Hanno Heinrichs of Crowdstrike   June 8, 2021
There was a bug, SonicWall did not fix it completely and eventually bad guys exploited the heck out of it. Quoting Pieter Arntz: "In the continuous wave of ransomware attacks you may have noticed a trend where the software and devices that are designed to keep you safe, are being used to establish the opposite. This year we have seen Pulse Secure vulnerabilities exploited in the wild, CISA warnings about successful attacks targeting a number of years-old vulnerabilities, and the colossal Kaseya supply-chain attack, among others."

JUNE 2021

Multiple Zyxel devices vulnerable to WAN side attack

Sophisticated hackers are targeting these Zyxel firewalls and VPNs
by Liam Tung of ZDNet   June 25, 2021
Bad guys are hacking into these Zyxel devices: Unified Security Gateway (USG), ZyWALL, the USG FLEX combined firewall and VPN gateway, Advanced Threat Protection firewalls, and VPN series devices. They are modifying the devices to gain entry into the network behind them. The official Zyxel response makes it sound as if the bad guys are abusing back door accounts built into the devices. If so, it would not be the first time. Earlier this year, researchers found a backdoor account in Zyxel firmware, which left 100,000 devices vulnerable.

Microsoft toots their own horn - finds bug in 10 year old Netgear consumer router

Microsoft finds new NETGEAR firmware vulnerabilities that could lead to identity theft and full system compromise
by Jonathan Bar Or of Microsoft 365 Defender Research Team   June 30, 2021
The buggy router, the NETGEAR DGN-2200 v1 series is really a combination modem/router. And, it is old as heck, the User Guide is dated February 2011. Yet, here we are, in June 2021 and Microsoft announces that they found bugs in it. This is really a PR stunt for Microsoft defensive software. That said, their software was triggered by "... a device owned by a non-IT personnel was trying to access a NETGEAR DGN-2200v1 router’s management port." Great catch, but who is using a 10 year old DSL modem/router and the latest and greatest Microsoft software? The router is as buggy as buggy gets. Any remote person can get full control of it. The worst bug lets you access any page in the web admin if you include one of the get-out-of-jail-free character strings in the GET request. Another bug exploits the encryption of the configuration backup file to learn the userid/password to login legitimately. The bugs are described in enough details to make someone not trust Netgear. The bugs have been fixed, which is quite a trick. You have to assume this router was End-of-Life years ago.

MAY 2021

Wi-Fi bugs in most every Wi-Fi device

Frag Attack
by Mathy Vanhoef of NYU   May 10, 2021
Shame on everyone for these Frag Attack bugs. Some of the Wi-Fi bugs are in the official specs for how Wi-Fi is supposed to work. For that, shame on the Wi-Fi Alliance, a group that has previously shown itself not to be up to the job. The rest of the bugs fall on many assorted programmers for not programming to the specs. Not just the programmers working for one company, but for many companies. Why so much shame? It is very likely that every Wi-Fi device in the world has at least one of the 12 bugs. Quoting Vanhoef: "In experiments on more than 75 devices, all of them were vulnerable to one or more of the discovered attacks." Bug fixes are need from dozens, if not hundreds, of sources. We'll get some, over time, but these bugs are sure to last for decades. The design flaws are difficult to exploit according to Vanhoef: "... the biggest concern are the programming mistakes in Wi-Fi products since several of them are trivial to exploit." One defense is HTTPS. A VPN helps with some of the bugs, but not all. Quoting: "Using a VPN can prevent attacks where an adversary is trying to exfiltrate data. It will not prevent an adversary from bypassing your router's NAT/firewall to directly attack devices." Interestingly, Wi-Fi 6 (aka ax) is more vulnerable than Wi-Fi 5 (aka ac). Vanhoef has worked with the Wi-Fi Alliance for the last nine months to get these bugs fixed. To date, five companies have released patches. Vanhoef gets in a dig at the Wi-Fi Alliance when he says "'s essential to regularly test Wi-Fi products for security vulnerabilities, which can for instance be done when certifying them." The Wi-Fi Alliance does this certification. We may be in good hands with Allstate, but that is not the case with the Wi-Fi Alliance. He also says the biggest risk is likely the ability to abuse these flaws to attack devices in someone's home network. He does not offer a defense, but I will - VLANs, or, at the least, Guest Wi-Fi networks. Or, a second router. The bug that scares me the most is the one that allows bad guys to bypass a router firewall and attack devices directly. He tested four consumer routers and found two were vulnerable, but he did not name names and did not say which of the 12 bugs they were vulnerable to. Check with your router vendor to see if they have anything to say about this. Likewise, fixes are needed for Access Points and operating systems.
How bad is this really? From the horse's mouth:
Does this mean every Wi-Fi device is trivial to attack?
"The design issues are, on their own, tedious to exploit in practice. Unfortunately, some of the implementation vulnerabilities are common and trivial to exploit. Additionally, by combining the design issues with certain implementation issues, the resulting attacks become more serious. This means the impact of our findings depends on the specific target. Your vendor can inform you what the precise impact is for specific devices. In other words, for some devices the impact is minor, while for others it's disastrous."

Still more bugs in Cisco RV34X routers

Advisory: Cisco RV34X Series – Privilege Escalation in vpnTimer
by T. Shiomitsu of the IoT Inspector Research Lab   May 5, 2021
"A few weeks ago, we published an advisory on the Cisco RV series routers, where we outlined the root cause for authentication bypass and remote command execution issues. This week, Cisco has released an advisory for another bug we reported around the same time: A privilege escalation issue, which could be used in combination with the other two issues to run arbitrary code with root privileges on affected RV34X devices. ". The bug is CVE-2021-1520 - Privilege Escalation in vpnTimer. A look at old firmware shows that the bug has been present since at least the first firmware update package of the RV34X series back in February 2017). Vulnerable routers are the RV340, RV340W, RV345 and the RV345P. A fix is available.

APRIL 2021

Bugs in Cisco RV34X series routers

Advisory: Cisco RV34X Series – Authentication Bypass and Remote Command Execution
by T. Shiomitsu of the IoT Inspector Research Lab   April 13, 2021
"In early 2021, we reported a few security issues to Cisco related to their RV34X series of routers, two of which have been recently patched. The issues in question were an authentication bypass and system command injection, both in the web management interface. These can be chained together to achieve unauthenticated command execution." Cisco took 4 months to release a fix (Jan 2, 2021 through April 7, 2021) and they admit that other devices are also affected. The bugs are CVE-2021-1472 - RV34X /upload Authorization Bypass Vulnerability and CVE-2021-1473 - RV34X OS Command injection in Cookie string.

Critical bug in Juniper Junos OS - fixes available

Critical Vulnerability Can Allow Attackers to Hijack or Disrupt Juniper Devices
by Eduard Kovacs of Security Week   April 16, 2021
A buffer size validation flaw may allow an unauthenticated remote attacker to send specially crafted packets to a vulnerable device, triggering a partial Denial of Service, or remote code execution. An attacker who successfully exploits the vulnerability can gain root access to the targeted system. The bug is in the overlayd daemon which runs as root by default and listens for UDP connections on port 4789. The underlying problem is improper buffer size validation, which can lead to a buffer overflow. The bug is CVE-2021-0254. Good news: Fixes are available and vulnerable devices are typically not exposed to the Internet. The bug was discovered by Nguyễn Hoàng Thạch with Singapore-based cybersecurity company STAR Labs.

MARCH 2021

Bug in D-Link DIR-3060 router

Advisory: D-Link DIR-3060 Authenticated RCE (CVE-2021-28144)
by IoT Inspector Research Lab   March 11, 2021
The D-Link DIR-3060 is affected by a post-authentication command injection vulnerability. Anybody with authenticated access to the router can run arbitrary system commands on the device as the system admin user, with root privileges. D-Link has released a patched firmware.

Bugs in Cisco RV132W and RV134W routers

CVE-2021-1287 Detail
by NIST   March 17, 2021
"A vulnerability in the web-based management interface of Cisco RV132W ADSL2+ Wireless-N VPN Routers and Cisco RV134W VDSL2 Wireless-AC VPN Routers could allow an authenticated, remote attacker to execute arbitrary code on an affected device or cause the device to restart unexpectedly. The vulnerability exists because the web-based management interface does not properly validate user-supplied input.... A successful exploit could allow the attacker to execute arbitrary code as the root user .... " The attacker needs to be authenticated to the device before they can exploit the flaw. Fixes are available.


Still more Cisco bugs

Cisco Warns of Critical Auth-Bypass Security Flaw
by Lindsey O'Donnell of Threatpost   February 25, 2021
"A critical vulnerability in Cisco Systems' intersite policy manager software could allow a remote attacker to bypass authentication. The vulnerability is one of three critical flaws fixed by Cisco on this week. It exists in Cisco’s ACI Multi-Site Orchestrator (ACI MSO) — this is Cisco’s management software for businesses ... The flaw stems from improper token validation on an API endpoint in Cisco’s ACI MSO. The vulnerability ranks 10 (out of 10) on the CVSS vulnerability-rating scale. The glitch is considered critical because an attacker - without any authentication - could remotely could exploit it..." Cisco also fixed a bug in their NX-OS network operating system for Nexus-series Ethernet switches. This flaw, which has a CVSS score of 9.8 out of 10, lets an unauthenticated, remote attacker create, delete or overwrite arbitrary files with root privileges on Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches.

Paying more does not get you better software

Fortinet fixes critical vulnerabilities in SSL VPN and web firewall
by Ax Sharma of Bleeping Computer   February 7, 2021
There are assorted bugs in the FortiProxy SSL VPN and FortiWeb Web Application Firewall (WAF) products. The worst bug is in the FortiProxy SSL VPN, it can be triggered by a remote, unauthenticated attacker using a specially crafted POST request. A SQL Injection flaw (CVE-2020-29015) lets an attacker get the hash of the administrator account due to excessive DBMS user privileges. A Buffer Overflow flaw (CVE-2020-29016) allows for arbitrary code execution by a remote attacker without the password.


SonicWall hacked using a bug in their own software

SonicWall firewall maker hacked using zero-day in its VPN device
by Lawrence Abrams of Bleeping Computer   January 23, 2021
"SonicWall is a well-known manufacturer of hardware firewall devices, VPN gateways, and network security solutions whose products are commonly used in SMB/SME and large enterprise organizations." They released an advisory warning that hackers used a bug in their Secure Mobile Access (SMA) VPN device and their NetExtender VPN client to attack their internal systems. Until the bug is fixed they suggest enabling two-faction authentication and blocking web traffic from countries that do not need to access their devices. Then:
SonicWall SMA 100 zero-day exploit actively used in the wild by Lawrence Abrams February 1, 2021
SonicWall is still investigating the vulnerability and has not provided many details. It likely affects their SMA 100 series of remote access appliances. Another suggested mitigation is restricting the IP addresses than can access the SonicWall management interface. Then:
SonicWall fixes actively exploited SMA 100 zero-day vulnerability By Lawrence Abrams February 3, 2021
They released a patch for the bug in the SMA 100 series of appliances running firmware version 10.x. Specifically: the SMA 200, SMA 210, SMA 400, SMA 410 and the virtual SMA 500v appliance. They have still not provided any details on the vulnerability. Tweets from the NCC Group indicate that it allows remote access to the management interface without authorization.

And ... still MORE Cisco bugs

Cisco reveals critical bug in small biz VPN routers when half the world is stuck working at home
by Simon Sharwood of The Register   February 5, 2021
This is as bad as bad gets. The worst bugs "can be exploited by an unauthenticated, remote attacker to execute arbitrary code as the root user. All the attacker needs to do is send a maliciously crafted HTTP request to the web-based management interface." Routers vulnerable to this are: RV160, RV160W, RV260, RV260P, and RV260W. Other bugs allow a remote bad guy, again without a password, to "conduct directory traversal attacks and overwrite certain files that should be restricted ...." Other Cisco routers, the RV016, RV042, RV042G, RV082, RV320, and RV325 have still other bugs. All the bugs seem to be due to lazy Cisco employees who can't be bothered to validate input. Four buggy routers, the RV016, RV042, RV042G, and RV082 are not getting updates because they are too old. If the bugs don't turn you away from Cisco, consider the tech support experience - they put most of the burden on you. These quotes are from the bug Advisories below.
You want the patches? "... customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner." You want to learn about available updates? Cisco won't tell you. "When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure..." Will the available update work on your hardware? You figure it out. "In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release." I don't even know what the last part of that quote means. The big point is that you pump your own gas when you are a Cisco customer. I would not use their hardware for a paper weight.

More Cisco bugs

High-Severity Cisco Flaw Found in CMX Software For Retailers
by Lindsey O'Donnell of ThreatPost   January 13, 2021
At this point, I would not trust or even want to touch any hardware or software from Cisco. Their software has too many bugs and this case shows their refusal to fix some bugs. Cisco addressed 67 high-severity bugs. That is far too many to have in software that is reasonably mature. Far too many. Sixty of the bugs exist in in the web-based management interface of Cisco Small Business RV110W, RV130, RV130W and RV215W routers. Quoting: "Of note, Cisco said it would not release software updates for the Cisco Small Business RV110W, RV130, RV130W and RV215W routers, as they have reached end of life."



Bugs bugs bugs bugs bugs bugs

Vulnerability Summary for the Week of December 28, 2020 Bulletin (SB21-004)
by the CISA branch of the US Government   January 4, 2021
A summary of new vulnerabilities that have been recorded in the past week. Again, just one week. Below is a summary of the CISA summary for assorted devices from networking companies. They may not all be routers and the severity of the bugs vary widely.
Tenda AC1200 (Model AC6) the default settings for the router speed test contain links to download malware CVE-2020-28094
Tenda AC1200 (Model AC6) a large HTTP POST request sent to the change password API will trigger the router to crash and enter an infinite boot loop. CVE-2020-28095
Tenda N300 F3 devices allow remote attackers to obtain sensitive information via a direct request for cgi-bin/DownloadCfg/RouterCfm.cfg CVE-2020-35391
Tenda AC1200 (Model AC6) userids: admin, support, user, and nobody have a password of 1234. CVE-2020-28093
Belkin LINKSYS RE6500 allow remote attackers to execute arbitrary commands or set a new password via shell metacharacters CVE-2020-35713
Belkin LINKSYS RE6500 allow remote attackers to cause a persistent denial of service (segmentation fault) CVE-2020-35716
Belkin LINKSYS RE6500 allow remote authenticated users to execute arbitrary commands via shell metacharacters in a filename CVE-2020-35715 and CVE-2020-35714
TP-Link: a password-disclosure issue in the web interface of certain TP-Link devices allows a remote attacker to get full administrative access to the web panel. CVE-2020-35575
Certain Zyxel products allow command injection by an admin via an input string to chg_exp_pwd during a password-change action. CVE-2020-29299
DrayTek Vigor2960 allows remote command execution via shell metacharacters in a toLogin2FA action to mainfunction.cgi. CVE-2020-19664
Certain NETGEAR devices are affected by disclosure of sensitive information. CVE-2020-35802
Certain NETGEAR devices are affected by a buffer overflow by an authenticated user. CVE-2020-35787
Certain NETGEAR devices are affected by command injection by an authenticated user. CVE-2020-35793
NETGEAR DGN2200v1 devices mishandle HTTPd authentication CVE-2020-35785
NETGEAR GS716Tv3 and GS724Tv4 are affected by CSRF. CVE-2020-35778
NETGEAR JGS516PE , JGS524PE, JGS524Ev2 and GS116Ev2 are affected by lack of access control at the function level. CVE-2020-35784
NETGEAR JGS516PE, JGS524Ev2, JGS524PE and GS116Ev2 are affected by incorrect configuration of security settings. CVE-2020-35801
NETGEAR NMS300 devices are affected by command injection by an authenticated user. CVE-2020-35789
NETGEAR NMS300 devices are affected by denial of service. CVE-2020-35780 and CVE-2020-35781
NETGEAR R7500v2, R8900, R9000 and R7800 are affected by command injection by an authenticated user. CVE-2020-35792 and CVE-2020-35791
NETGEAR RBS40V, RBK752, RBR750, RBS750, RBK852, RBR850 and RBS850 are affected by command injection by an authenticated user. CVE-2020-35794
NETGEAR WAC104 devices are affected by a buffer overflow by an authenticated user. CVE-2020-35788
NETGEAR D6200, D7000, JNR1010v2, JR6150, JWNR2010v5, R6020, R6050, R6080, R6120, R6220, R6260, WNR1000v4, WNR2020 and WNR2050 are affected by stored XSS. CVE-2020-35840 and CVE-2020-35842
NETGEAR R7800 is affected by a buffer overflow by an authenticated user. CVE-2020-35786
NETGEAR D7800, R7500v2, R7800, R8900, R9000, RAX120, RBK50, RBR50, RBS50, XR500 and XR700 are affected by stored XSS. CVE-2020-35824 and CVE-2020-35830 and CVE-2020-35835
NETGEAR D7800, R7800, R8900, R9000 and XR700 are affected by disclosure of sensitive information. CVE-2020-35804 and CVE-2020-35838 and CVE-2020-35837
NETGEAR R6400v2, R6700v3, R6900P, R7000, R7000P, R7800, R7850, R7900, R7960P, R8000, R7900P, R8000P, RAX15, RAX20, RAX200, RAX45, RAX50, RAX75, RAX80, RBK752, RBR750, RBS750, RBK852, RBR850, RBS850, RBK842, RBR840, RBS840, RS400 and XR300 are affected by command injection by an unauthenticated attacker. CVE-2020-35798
Just ... one ... week.

Critical bug in D-Link DSR VPN routers

D-Link VPN routers get patch for remote command injection bugs
by Ionut Ilascu of Bleeping Computer   December 8, 2020
No one makes money saying that newly discovered bugs are not that big a deal. So, this trio of D-Link bugs may or may not be a big deal, despite the fact that everyone says the sky is falling. To be clear, the most critical of the three bugs is indeed the worst possible type of flaw - anyone on the Internet can totally hack these routers. What is not said, however, is whether the web interface to these routers is exposed to the Internet by default. If not, this is much less of an issue. I suspect the web interface is not available remotely because if it was, the company that found these bugs would say so. Either way, D-Link should say something about this in their response, but, they do not. They don't care about security. Further proof about how little D-Link cares about security is the timeline. Three bugs were reported to them on August 11, 2020. Their first response was early December 2020. They fixed two of the bugs and consider the third not a real problem. The most critical bug can also be exploited on the LAN but VLANs can be used to limit access to the web based Admin interface. At least on good routers they can. I don't know if these routers support VLANs. The bugs affect the DSR-150, DSR-250, DSR-500 and DSR-1000.


Avoid routers from Jetstream and Wavlink

Walmart-exclusive router and others sold on Amazon and eBay contain hidden backdoors to control devices
by Bernard Meyer of   November 23, 2020
This expands on a problem first noticed in April 2020. Quoting: "In a collaboration between CyberNews Sr. Information Security Researcher Mantas Sasnauskas and researchers James Clee and Roni Carta, suspicious backdoors have been discovered in a Chinese-made Jetstream router, sold exclusively at Walmart as their new line of 'affordable' wifi routers. This backdoor would allow an attacker the ability to remotely control not only the routers, but also any devices connected to that network ... the cybersecurity research team also discovered that low-cost Wavlink routers, normally sold on Amazon or eBay, have similar backdoors. The Wavlink routers also contain a script that lists nearby wifi and has the capability to connect to those networks ... While Jetstream has an exclusive deal with Walmart, and is sold under other brand names like Ematic, there is very little information available about which Chinese company actually produces these products ... While Clee's original research (and follow-up) analyzed one Wavlink router, our new analysis shows that multiple Wavlink and Jetstream devices have now been shown to be affected. In fact, all of the devices that the team analyzed were found to contain backdoors.

Routers from Asus and TP-Link hacked at a hacking contest

Routers, NAS Devices, TVs Hacked at Pwn2Own Tokyo 2020
by Eduard Kovacs of Security Week   November 9, 2020
Update: Dec 17, 2020: I am tracking the acknowledgment and/or fix for the Asus router on the News page. So far, nothing.
Update Nov 13, 2020: It appears that one of these articles was wrong. The Netgear router was not hacked. Also, the TP-Link router is not sold in the US.
The three routers that have been reportedly been hacked at the contest are the ASUS RT-AX86U, the TP-Link TL-WDR7660 and the NETGEAR Nighthawk R7800. Two bugs were found in the Netgear router. The bugs will be disclosed to the hardware manufacturers and hopefully fixes will be released. What no one will say is whether the same bugs exist in other routers from these companies.


The second critical flaw for SonicWall this year

800,000 SonicWall VPNs vulnerable to new remote code execution bug
by Catalin Cimpanu of ZDNet   October 15, 2020
SonicWall Network Security Appliances are used as firewalls and SSL VPN portals to control access internal and private networks. The Tripwire VERT security team discovered a bug that exists in almost 800,000 internet-accessible SonicWall VPN appliances. The bug is considered critical and is expected to come under active exploitation once proof-of-concept code is made publicly available. The underlying problem is a stack-based buffer overflow. To exploit the bug, bad guys do not need to have valid credentials. Oh, and the bug is trivial to exploit, even for unskilled attackers. This is SonicWall's second major bug this year. Patches are available.

JULY 2020

Asus router bug and insight into Asus itself

ASUS Router Vulnerable to Fake Updates and XSS
by Martin Rakhmanov of Trustwave   July 23, 2020
Rakhmanov found two bugs in the ASUS RT-AC1900P router and the company has fixed them. One bug (CVE-2020-15498) was that the firmware update process accepted software with forget server certificates. This would have let spies and hackers install their own firmware on their router. An attacker would have to be adjacent network-wise to the router to perform this man in the middle attack, but it could result in a full compromise of the router. The other bug (CVE-2020-15499) was an XSS in a dialog window of the admin interface. There are two things here that are very important, much moreso than the bugs themselves. Neither ASUS nor Rakhmanov said anything about other ASUS routers. It is very likely they too are vulnerable, but it is none of our business. Then too, there is the way Asus handled this. For one thing they never issued a security advisory. And, as we see below in the Revision History, they could not be bothered to tell Rakhmanov when they fixed the bug. And, when he asked they were not sure if they fixed one or both bugs.

Multiple D-Link router bugs

5 severe D-Link router vulnerabilities disclosed, patch now
By Ax Sharma of Bleeping computer   July 24, 2020
It is not clear from this story which routers are buggy. The research the story is based on is for a router that is End-of-Life (no more bug fixes, it's too darn old to bother with). The bugs are in the web interface to the router, as they often are. Best practices for router security is always to limit LAN side access to the router's admin interface, and, of course, to disable remote administration. I found one bug quite noteworthy. It lets a bad guy bypass the router password by adding a couple parameters to the HTTP request to the router. The same flaw was reported in 2010 and again in 2011. That tells you all you need to know about D-Link.

Way too many bugs in Cisco software

Cisco releases security fixes for critical VPN, router vulnerabilities
by Charlie Osborne for ZDNet   July 17, 2020
For the most part, I leave out Cisco bugs from this page because there are just too many of them. The number of critical bugs in Cisco software over the years has been far too high. I would not use their products. Cisco just released fixes for 34 bugs, five of which are the most critical in that they allow bad guys to get total control of vulnerable devices. One issue is the Telnet service in the Small Business RV110W Wireless-N VPN Firewall router. It has a default, static password that, if obtained by attackers, can lead to the full remote hijacking of a device. This is a mistake that can not be forgiven and not the first time Cisco has had hard coded passwords. A flaw in the management interface of the Cisco Small Business RV110W, RV130, RV130W, and RV215W routers can be exploited to execute arbitrary code as the root user. This is a very common flaw, improper validation of input. Translation: lazy programmers. Same thing with the web interface of the Cisco RV110W VPN Firewall and RV215W VPN router.

Do not buy a router from Tenda

Tenda AC15 AC1900 Vulnerabilities Discovered and Exploited
by Sanjana Sarda of Independent Security Evaluators   July 10, 2020
Their research uncovered five bugs including two methods attackers can use to gain persistent unauthenticated root access to the router. They also found 7 open LAN side ports. Much of this article is focused on the specifics on the bugs and it leaves out the implications. Are the bugs exploitable LAN side or WAN side or both? Does a user have to be logged in to exploit the bug or not? Despite this, the article is very useful at the end. ISE first contacted Tenda in January 2020. Here, six months later, no response from Tenda at all. And, as always with router bugs, it is likely that similar flaws exist in other firmware versions and other Tenda routers.

JUNE 2020

79 Netgear devices are buggy and the company did nothing

SOHO Device Exploitation
by Adam of Grimm   June 15, 2020
Quoting: "This is just one more example of how SOHO device security has fallen behind as compared to other modern software ... As such, it’s trivial to overflow the stack buffer." The author found a pre-authentication stack overflow vulnerability in the Netgear R7000 router running firmware version The vulnerability, which allows for remote code execution, has been present in the R7000 since it was released in 2013. But that is only the beginning. Adam was able to identify 79 different Netgear devices and 758 Netgear firmware images that included the buggy code. The oldest buggy firmware dated back to 2007. The vulnerability was reported to Netgear on May 7, 2020 and they seemed to have ignored it. Using assorted scripts, Adam created an exploit for each of the 758 buggy firmware images. Then, he tested his exploit on 28 of the vulnerable devices to ensure that it worked as expected. Among the confirmed buggy routers are the Netgear R6250, R6300v2, R6400, R7000, R8000, R8300 and the R8500. Criticizing Netgear he said "In addition to lacking stack cookies, the web server is also not compiled as a Position-independent Executable (PIE), and thus cannot take full advantage of ASLR. As such, it’s trivial to find a ROP gadget within the httpd binary ... that will call system with a command taken from the overflown stack."

Bugs in a very old D-Link router

D-Link leaves severe security bugs in home router unpatched
by Ionut Ilascu of Bleeping Computer   June 12, 2020
The D-Link DIR-865L router was released in 2012 and is no longer supported for U.S. consumers. However, on the website for European countries, the status is "End of Sale" which means that it can no longer be purchased but it is still supported by the vendor. Researchers at Palo Alto Networks' Unit 42 found and reported six security vulnerabilities in the DIR-865L in late February 2020. Now, over three months later, D-Link released beta firmware that fixes three of the six flaws. Two bigger issues: 1) What about other models? Unit 42 warned that newer routers may be vulnerable to the same flaws because they share a common code base. A good router vendor will check for the same flaw in all their products. A bad router vendor will not. The response from D-Link said nothing about any other models. 2) Who cares about such an old router? Why is Unit 42 even looking at ancient consumer devices? In the US, the DIR-865L went out of support in Feb. 2016.

APRIL 2020

Wavlink does not respond to security flaws - another brand to avoid

Multiple Vulnerabilities in Wavlink Router leads to Unauthenticated Remote Code Execution
by James Clee   April 18, 2020
Clee started a new hobby - buying cheap Chinese technology to see what he could find out about security. He startee with the Wavlink WL-WN530HG4 which sells for $30. An interesting read that resulted in CVE-2020-10971 and CVE-2020-10972. He found back doors and miserable password verifications. Quoting: "... so an attacker with the right background information about the device could achieve RCE fairly easily." Worse, is that he attempted multiple times to contact Wavlink using several different support contacts and they ignored him. This is not a company you want to deal with.
A few days later he wrote about the Wavlink WL-WN579G3 and WL-WN579A3 Wi-Fi Extenders. They were just as bad as the router. He found that lots of web pages are externally accessible without authentication and they contain sensitive data. He could get the username and password without authenticating to the devices. Once again, Wavlink did not respond to any of his attempts at communication.

Sophos quickly issues patch for their firewalls

Hackers are exploiting a Sophos firewall zero-day
by Catalin Cimpanu for ZDNet   April 26, 2020
Bad guys were found to be attacking a previously unknown SQL injection vulnerability in the Sophos XG enterprise firewall. Sophos learned about the problem on April 22nd when a customer reported something strange. They published an emergency security update on April 25th. The firewalls can self-update, though I doubt every user has that enabled. No surprise to learn that vulnerable firewalls had either their administration or User Portal control panel exposed to the Internet. The bug let bad guys steal files from the XG firewall, and those files could include usernames and hashed passwords for the firewall administrator, for the firewall portal admins and for user accounts used for remote access to the device. Bad guys could also learn the firewall's license and serial number, and see some user emails. Sophos researchers named the malware Asnarok. From what I have seen, the Sophos response was great. You could not ask for more. Not only did they fix the bug quickly, they also documented the heck out of the issue.

MARCH 2020

Multiple issues with OpenWRT

Uncovering OpenWRT remote code execution (CVE-2020-7982)
by Guido Vranken of ForAllSecure   March 24, 2020
The OpenWRT package manager, opkg, does not check the SHA256 hash of anything it downloads. This is compounded by it downloading updates over HTTP rather than HTTPS. In addition, the opkg unpacker is buggy; malformed data leads to a variety of memory violations. opkg on OpenWrt runs as root with write access to the entire filesystem, so arbitrary code could be injected by means of forged .ipk packages with malicious payloads. Also vulnerable is the LEDE fork of OpenWRT. One of the bugs was introduced in February 2017. Fixes are available.

Two Zero Day bugs in DrayTek routers (Updated)

A mysterious hacker group is eavesdropping on corporate email and FTP traffic
by Catalin Cimpanu of ZDNet   March 28, 2020
According to Netlab, the network security division of Chinese security firm Qihoo 360, bad guys have been hacking into DrayTek routers to eavesdrop on FTP and email traffic. They first observed this in early December 2019. There are two different zero-day flaws in three DrayTek Vigor devices, the 2960, 3900 and 300B. The bugs could allow for arbitrary code execution on a vulnerable system. This could allow an attacker to eavesdrop on network traffic, operate SSH and Web based backdoors, and create system accounts. One flaw is in the login mechanism and it allows attackers to hide malicious code inside the router's username field. This malicious code can grant the hackers control over the router. Next, the attackers started recording traffic coming to port 21 (FTP), 25 (email), 110 (email) and 143 (email). These are four very old protocols and they still use plain text. It is assumed the attackers were looking for FTP and email passwords. The second flaw is in the "rtick" process and attackers used it to create backdoor accounts on the hacked routers. Qihoo says that around 100,000 vulnerable DrayTek devices are online. DrayTek issued updated firmware six days after they learned of the problem. And, DrayTek impressed me with this " The issue only affects the Vigor3900 / 2960 / 300B and is not known to affect any other DrayTek products". This is rare, vendors usually fix only the devices with the reported problem.

Multiple flaws in multiple Netgear routers

Thousands of Netgear routers are at risk of getting hacked: What to do
by Paul Wagenseil of Toms Guide   March 5, 2020
Nearly 50 Netgear devices need firmware patches ASAP. The devices are seven modem-router gateways, 40-odd routers (including some Nighthawk and Orbi models) and one range extender. The worst of the flaws lets attackers remotely install malware on one router. A "pre-authentication command injection security vulnerability" on five routers could also lead to total network takeover. For a number of the flaws Netgear has not provided specific details. Does your Netgear router need an update? Turns out, this is a hard question to answer. Netgear does a terrible job of communicating to its customers what each router's model number is. They hardly ever use the actual model number in their consumer marketing and packaging. For example, the AC4000 Nighthawk X6S Tri-Band WiFi Router is the R8000P. To find the model number, turn the device over and look at the sticker on the bottom. The update procedure differs among the various routers. The article has a full list of the buggy router model numbers.


Millions of Internet boxes are vulnerable

Cable Haunt
by Lyrebirds ApS   January 11, 2020
Bad news: untold millions of devices are vulnerable. Good news: it is not easy to exploit the bug. Bad news: despite all the headlines, it is not only modems that are vulnerable, so too are gateways (combination modem/router). Bad news: In the US, this will never be fixed. ISPs are virtual monopolies and thus have no reason to do a good job. Fixing this takes time, effort and money and few very customers will ever learn about it. I tried to get a response from Spectrum, it was a waste of time. The company that found the flaw offered a tester script for Linux that seems useless. They also offered some JavaScript that can copied and pasted into a browser console to test if your Internet box is vulnerable. With their JavaScript, I confirmed that the Netgear CM600 modem is vulnerable. They leave out that you need to copy/paste their Javascript as a whole, not each line individually. And, you may need to change the port number, which is why I suggest using nmap below. Netgear only offers free tech support for the first 90 days, so I can not ask them about this. Not that it matters, modem firmware can only be updated by an ISP, at least in the US.
What to do?
I suppose you could try and learn the firmware version that your modem or gateway is running and then try to find out if it has been patched for the Cable Haunt flaw. In the US, this is almost definitely a waste of time.
First, see if your Internet box uses Broadcom. If not, you are safe. The Toms Guide article below has links to pages that show this for Arris and Netgear devices. For other companies see If that fails, perhaps look for the technical specs of your modem or gateway. Maybe try to contact the hardware manufacturer. If Broadcom ...
If you have a router/modem combination box, run nmap on the LAN side IP address looking at all 65,535 TCP ports. If you have a router and a modem as stand-alone devices, run the same nmap against After the nmap scan, try to use HTTP and HTTPS to access every open port. The buggy Spectrum Analyzer looks like this on a Netgear modem. Found a Spectrum Analyzer? If so, nag either your ISP or the hardware vendor for fixed software. Lotsa luck (probably won't happen). Better yet, block access to the buggy device. If its a combination modem/router, there should be some sort of LAN side restrictions about which devices can logon to the box. For more, see the Security Checklist page here, the section on Local Administration. If you have a router and a modem as separate devices, you need a nerd to configure a defense. One option is something called a static route - some routers let you configure this, some do not. If your router supports firewall rules (rare), see my blog below about creating an outbound firewall rule to block modem access. As a rule consumer routers, such as AmpliFi from Ubiquiti or Google WiFi do not offer outbound firewall rules.



Multiple bugs in Ruckus Access Points

A ton of Ruckus Wireless routers are vulnerable to hackers
by Zack Whittaker of TechCrunch   December 28, 2019
Despite the headline, the buggy devices are Access Points not routers. Security researcher Gal Zror discovered 10 bugs in Ruckus devices. Three are biggies. They are in the web interface of the Unleashed line of APs. The flaws let a bad guy take complete control of a vulnerable router remotely and without needing a password. As bad as bad gets. Patches have been issued but the routers do not self-update. Ruckus Cloud access points are not buggy. Neither are their SmartZone-enabled devices. This was made public at a presentation at the 36th Chaos Communication Congress called Lecture: Don't Ruck Us Too Hard - Owning Ruckus AP Devices. This surprised me. For one, its the first mention of Ruckus in my list of bugs. Second, Ruckus is a high end company. Then again, Cisco is also high end and their software has a terrible track record when it comes to bugs and flaws and vulnerabilities.

More buggy D-Link routers

D-Link DIR-859 —Unauthenticated RCE (CVE-2019–17621)
by Miguel Méndez Z.   Decembe 24, 2019
Back in Oct. 2019, we learned of a Remote Code Execution bug in a single D-Link router, the DIR-859 (CVE-2019-17621). The bug could be exploited by anyone on the LAN to take full control of the router. Of course, many routers from the same company share the same firmware (operating system) so it was not a surprise when, in Nov. 2019, we learned that many more D-Link routers share the same bug. Some of the buggy routers are too old and will not be updated. Some have already had fixes released. Still more, are slated to have fixes released soon. These are the buggy models: DIR-818Lx DIR-822, DIR-823, DIR-859, DIR-865L, DIR-868L, DIR-869, DIR-880L, DIR-890, DIR-885, DIR-895. In some cases, the router firmware must be updated twice. Ugh. The vulnerability is in the code used to manage UPnP requests.

Four buggy TP-Link routers

TP-Link Archer Router Vulnerability Voids Admin Password, Can Allow Remote Takeover
by Grzegorz Wypych and Limor Kessem of IBM X-Force Red   December 16, 2019
There are critical bugs in the TP-Link Archer C5 v4, Archer MR200v4, Archer MR400v3 and the MR6400v4. Are other TP-Link routers safe? Don't know. No one said anything about other routers having been tested. The bug lets a bad guy take full admin control of the router. First, the bad guy has to trick the router as to the source of a login request. This is not hard. Then, the bad guy simply has to provide a password that is the wrong length. If the password is too short, it locks out access to the router. If the password is too long, it voids the current password letting the bad guy login without a password. TP-Link never fails to impress. Firmware updates are available. However, as the article below by Paul Wagenseil details, the firmware update process is miserable. The Archer MR200, MR400 and MR6400 are LTE-based routers sold in the European Union. The Archer C5 AC1200 is a home Wi-Fi router, sold in many countries.


More buggy D-Link routers that will not be fixed

D-Link Adds More Buggy Router Models to 'Won’t Fix' List
by Tom Spring of ThreatPost   November 19, 2019
A new bug in D-Link routers will not be fixed because the routers are too old to bother with (they are End-of-Life or EoL). The bug allows a bad guy, who does not know any passwords, to access the web configuration interface of the router. The buggy devices are: DIR-866, DIR-655, DHP-1565, DIR-652, DAP-1533, DGL-5500, DIR-130, DIR-330, DIR-615, DIR-825, DIR-835, DIR-855L, and DIR-862. D-Link suggests disabling remote administration, resetting the affected routers and using a complicated router password. It is not clear if this bug is similar to the bug (CVE-2019-16920) that FortiGuard Labs reported last month. That bug impacted 10 of the same routers. Spring puts this bug in perspective, noting a long history of bugs in D-Link routers. A September 2019 bug can leak passwords. A May 2019 bug allowed DNS hijacking. In 2017, we learned that the D-Link DIR-130 was one of 25 routers that could be exploited by the CIA. Also in 2017, the 850L and AC1200 had multiple vulnerabilities that could allow a hacker to gain remote access and control of device.

Zero Day flaw in the D-Link DIR-878 router. Others too?

Tianfu Cup Round-Up: Safari, Chrome, D-Link Routers and Office 365 Successfully Hacked
by Elizabeth Montalbano of ThreatPost   November 18, 2019
Hackers, at the annual Tianfu Cup gathering over the weekend, successfully compromised the D-Link DIR-878 router using a zero-day vulnerability. Note the plural use of the word hackers. The router was hacked by seven, yes, seven, different groups. It has been a few days and, so far, no response from D-Link on their security bulletin page. Will they acknowledge the flaw? Will they fix it? Time will tell. The bigger picture, however, involves other D-Link router. It is likely that other similar routers share the same buggy software. And, some recent history: in March 2019 the German Federal Office for Information and Security (BSI) issued a warning about bugs in the DIR-878 and the DIR-825. The bugs are easily exploited and let attackers bypass the logon processes and execute malicious code.


Ten D-Link routers that should be thrown away

Multiple D-Link routers vulnerable to remote command execution
by US Cert   October 23, 2019
These 10 D-Link routers are buggy, will not be fixed and should be thrown away: DIR-655, DIR-866L, DIR-652, DHP-1565, DIR-855L, DAP-1533, DIR-862L, DIR-615, DIR-835 and the DIR-825. A remote, unauthenticated attacker may be able to execute commands with root privileges on a buggy router. This can happen as the result of viewing a specially-crafted web page. The bug was publicly disclosed by Fortinet's FortiGuard Labs, same as below. This appears to be the same bugs as below, just that is has been found in six more routers.

D-Link won't fix bugs in four of its routers

D-Link Won't Fix Serious Security Flaw on Four Wi-Fi Routers
by Paul Wagenseil of Tom's Guide   October 8, 2019
Beware the D-Link DIR-652, DIR-655, DIR-866L and DHP-1565 routers. They have critical bugs. An attacker halfway across the world could hijack these routers without needing a password. Everyone suggests throwing these routers away. I agree. End of Life is the techie term for the computing devices that are too old to bother with. As Seinfeld might have said: No bug fixes for you! Manufacturers win twice with routers that are deemed EoL: they don't have spend money fixing bugs and they motivate customers to buy new routers. Usually EoL devices are no longer sold. Not so with D-Link. Three of them can still be bought new from third-party sellers on Amazon's U.S. website. Is the same bug in any other D-Link routers? None of our business. Fortinet, which found the bug, does not say which or how many routers they tested. And, the D-Link response is limited to these four routers with no mention of any others.


Bugs Bugs Bugs - 125 in all

SOHOpelessly Broken 2.0
by Independent Security Evaluators   September 16, 2019
My summary is on the News page.

Here we go again - another LAN side protocol available on WAN

Protocol used by 630,000 devices can be abused for devastating DDoS attacks
by Catalin Cimpanu of ZDNet   August 27, 2019
Just as with UPnP all those years ago, routers (and IoT devices) are exposing a protocol meant exclusively for LAN-side use to the Internet at large. This time the protocol is WSD (a.k.a. WS-Discovery and Web Services Dynamic Discovery). Bad guys abuse WSD to create DDoS attacks. WSD listens on UDP port 3702 (some articles also referenced TCP port 3702). Like UPnP, WSD is a protocol for LAN side devices to discover each other and their capabilities. Is there a printer in the house? WSD communication starts with requests to the IPv4 multicast address IPv6 uses FF02::C (link-local scope). Being exposed to the WAN is only one bug, the other is that devices should only respond to requests to these two IP addresses. WSD responses sometimes come from port 3702, sometimes from random high numbered ports. Akamai noted that most vulnerable devices were CCTV cameras and DVR systems. No article said anything about the failure of the routers to block these vulnerable devices. UPnP haunts us still.


Four router vendors refuse to fix bugs

Cross-Router Covert Channels
by Adar Ovadya, Rom Ogen, Yakov Mallah, Niv Gilboa and Yossi Oren of Ben-Gurion University   August 2019
Researchers at Ben-Gurion University found multiple ways to communicate between the two Wi-Fi networks typically offered by a router. They refer to these two networks as Host and Guest, most people refer to them as Private and Guest. The research was presented at the 13th USENIX Workshop on Offensive Technologies (WOOT). They tested routers from TP-Link, D-Link, Edimax and Linksys and all the companies refused to fix anything. Quoting: "We sent a draft of our findings to the manufacturers of the routers ... during May 2019. During June 2019 the Belkin/Linksys security response team notified us that they do not intend to fix the vulnerability we disclosed. None of the other router vendors responded to our disclosure". As I say elsewhere on this site, don't use a consumer router. The bugs are pretty obscure. For example, on some routers, a DHCP NAK from one network is erroneously sent to the other network which can be used to send a small amount of data to the other network. They also discovered that quickly joining and leaving an IGMP group from the Private network caused an IGMP Membership Query packet to be sent to both the Private and Guest networks. This too can be used transfer data between the two networks. There were also some timing attacks.

Bugs found in multiple 4G Hotspots

Reverse Engineering 4G Hotspots for fun, bugs and net financial loss
by G Richter of Pen Test Partners   August 10, 2019
A 4G hotspot is a router. The biggest difference is that it connects to the Internet via 4G rather than an Ethernet cable. Pen Test Partners found multiple vulnerabilities in several well known vendors Mi-Fi devices, including pre- and post-auth command injection and code execution. The vendors involved were generally poor at responding to disclosure attempts. ZTE was the worst, they responded that a device was end of life, so the bugs would not be fixed ... yet they were still selling it from their own online store! They also found bugs in Netgear and TP-Link devices.

JUNE 2019

Critical bugs in four TP-Link Wi-Fi Range Extenders

Critical RCE Vulnerability in TP-Link Wi-Fi Extenders Can Grant Attackers Remote Control
by Grzegorz Wypych of Security Intelligence   June 18, 2019
Four TP-Link Wi-Fi extenders have a critical remote code execution (RCE) vulnerability. The bug lets a remote attacker get complete control over the device. The attacker does not need to login or authenticate to the device to exploit the bug. The problem is triggered with a malformed user agent field in HTTP headers. The buggy devices are the RE365 (sold in Europe), the RE650 (sold in the US, UK and Canada), the RE350 (same 3 countries) and the RE500 (sold in the US and Canada). Patches have been issued but device owners have to manually download them and install them. First, they have to insure the correct hardware version for the available firmware, then they have to get the firmware for their country. All processes on these devices run with root-level access which is just asking for trouble.

Still another critical bug in Cisco software

Cisco IOS XE Software Receives Fix Against High-Severity Flaw
by Ionut Ilascu of Bleeping Computer   June 13, 2019
Far too much of this web page is devoted to bugs in Cisco software. They just released an updated version of their IOS XE operating system to patch a high severity bug - insufficient cross-site request forgery (CSRF) protections in the web-based user interface of the software. The bug can be exploited by an unauthenticated, remote attacker who could persuade an already logged in user of the web interface to follow a malicious link. The link could then perform arbitrary actions with the privilege level of the victimized user. If the victim is an administrator, bad guys could modify the configuration, run commands and even reload a vulnerable device. The good news is that a victim has to be logged in to the system before they can be exploited. Also, exploitation requires the HTTP Server feature to be active and it is not always active by default (this is version dependent).

MAY 2019

Cisco screws up for the millionth time

Thrangrycat   by Red Balloon Security   May 21, 2019
Take a look at the bugs tracked on this site. Lots of Cisco issues over the last few years. Paraphrasing Red Balloon: There are two bugs that affect about 150 different Cisco devices. The first, known as Thrangrycat, allows an attacker to fully bypass the Trust Anchor module (TAm) via Field Programmable Gate Array (FPGA) bitstream manipulation. This is due to multiple hardware design flaws in the TAm. The second is a remote command injection vulnerability against IOS XE version 16 that allows remote code execution as root. By chaining these, an attacker can remotely and persistently bypass Cisco’s secure boot mechanism and lock out all future software updates to the TAm. The TAm is a proprietary Cisco hardware security module. It is the root of trust that underpins all other Cisco security mechanisms. Thrangrycat allows an attacker to make persistent modification to the TAm, thereby defeating the secure boot process and invalidating the chain of trust at its root. While the flaws are based in hardware, they can be exploited remotely. Since the flaws involve the design of the hardware, it is unlikely that any software patch will fully resolve the fundamental issues. Cisco released a patch for IOS XE and provided the Cisco IOS Software Checker to identify vulnerabilities in Cisco IOS and IOS XE. Cisco is working on patches for Thrangrycat, but notes that the patch will not be a straightforward update for most devices but instead will require "on-premise[s] reprogramming of a low-level hardware component." Patches for many routers, switches and network interface modules will be released between May 2019 and November 2019. As for detection and mitigation, Red Balloon will present this in a talk at BlackHat USA 2019.

TP-Link publicly shamed

Thousands of vulnerable TP-Link routers at risk of remote hijack
by Zack Whittaker of TechCrunch   May 22, 2019
Thousands of TP-Link routers are vulnerable to a bug, and it took more than a year for TP-Link to publish the patches on its website. They created the patches, they just didn't publish them. The bug lets a low-skilled attacker to get full remote access to a vulnerable router. The bug was first disclosed to TP-Link in October 2017. Shortly thereafter, they released a patch for the WR940N router. But, the WR740N was vulnerable to the same bug and no patch was released for it. TP-Link was warned about this in January 2018, yet ... nothing until they were publicly shamed by TechCrunch.

Linksys found to be both incompetent and unconcerned with security

Over 25,000 Linksys Smart Wi-Fi routers vulnerable to sensitive information disclosure flaw
by Troy Mursch   May 13, 2019
Thirty three Linksys routers are buggy and Linksys will not fix it. They tried to fix it five years ago, but they screwed that up. Yet another confirmation of the opinion I offered on this site from the get-go back in 2015 - avoid consumer routers. The flaw affects Linksys Smart Wi-Fi routers. It allows unauthenticated remote access to sensitive information and its easily exploited by bad guys with little technical knowledge. The routers leak information both about themselves and about every (yes, every) device that has ever connected to them. For connected devices, Linksys always leaks the MAC address, Device name ("TROY-PC") and Operating system. Sometimes it also leaks the device type, model number, and a description of the attached device. As for router information, it leaks the model number, hardware version, serial number, firmware release level, MAC address, the LAN side IP address, WAN settings, firewall status and DDNS settings. Leaking the MAC address lets bad guys determine the physical location of the router. Data provided by BinaryEdge, shows that 25,617 Linksys Smart Wi-Fi routers are currently leaking sensitive information to the public. Among the 33 buggy models are the E4200, EA2700, EA5800, EA6900, EA7300, EA8500, EA9200, WRT1900AC, WRT3200ACM, XAC1900 and WHW03 Velop. The full list is here. This is yet another in a long line of HNAP bugs. The bug can also reveal if a router is using the default password (thousands are) without even trying to login. The worst part is that Linksys tried to fix this five years ago but clearly screwed that up. Then, when contacted about it recently, they had no interest in fixing it properly. Yes, if you disable remote web access you block the information leak. However, Linksys Smart Wi-Fi routers require remote access for the Linksys App to function.

APRIL 2019

29 new Cisco Bugs

Cisco warns over critical router flaw
by Liam Tung of ZDNet   April 18, 2019
Cisco has disclosed 29 new vulnerabilities, 5, 6 or 7 of which are doozies. Its too much for tech reporters to digest. One of the critical bugs is in the ASR9000 Series Aggregation Services Routers. The bug is as bad as bad gets, it can be exploited remotely by a bad guy without a password. There is a patch and a workaround. The other critical bugs affect Cisco Wireless LAN Controller software. Another bug is in the Cisco Expressway Series and Cisco TelePresence Video Communication Server. Another biggie is in Cisco Aironet Series Access Points. Finally, there is a critical bug in the Cisco Cluster Management Protocol code in Cisco IOS and Cisco IOS XE. As with the first bug a remote bad guy without a password can obtain full control of vulnerable devices. If the devices accept Telnet connections, a bad guy who sends malformed Telnet options while establishing a connection can execute arbitrary code. The Threatpost article below offers some context, noting that earlier this month, Cisco re-patched flaws for two high-severity bugs after their first attempt was botched. And, they reported two new router bugs with no fixes or workarounds. Just what you want in a router vendor.

TP-Link, yet again

Buffer Overflow Vulnerability in TP-Link Routers Can Allow Remote Attackers to Take Control
by Grzegorz Wypych and Limor Kessem of IBM Security Intelligence   April 8,2019
There is a buffer overflow flaw in the TP-Link TL-WR940N and TL-WR941ND routers. No other models were tested, so it is likely that others in the same family are vulnerable too. These models are old (they are 300Mbps Wi-Fi N) and have been discontinued. The bug allows bad guys to take control of the device from a remote location. Sounds worse than it is. You have to already be logged on to the web interface to exploit the flaw. And, the flaw is in the web interface, so if Remote Administration is disabled, as it often is, then it can not be exploited from overseas. TP-Link issued patches. Why are so many of these reports about ancient routers? Perhaps because if you break a $30 router while hacking it, no big deal.

Three bugs in a Verizon FIOS router

Verizon Fios Quantum Gateway Routers Patched for Multiple Vulnerabilities
by Tenable Research   April 9, 2019
Tenable has discovered 3 vulnerabilities in the Verizon Fios G1100 Quantum gateway/router. A Command Injection flaw can only be exploited by a user already logged on to the device. It is exploitable from the LAN side and remotely if Remote Administration is enabled. Because HTTPS is not enforced in the web interface, an attacker on the LAN side can intercept login requests using a packet sniffer and then replay the requests to get admin access to the web interface of the router. Packet sniffing a login request also provides a salted password hash (SHA-512). An unauthenticated attacker can retrieve the password salt simply by visiting a URL in a web browser. Thus, an attacker could perform an offline dictionary attack to recover the original password. Of course, the focus on passwords is because insecure firmware, like this, always uses the same userid. By now, most Verizon FIOS customers should have the updated firmware. If you have a G1100 you should verify this. The real lesson here is not use hardware from an ISP. See the Disclosure Timeline in the first article below and judge the Verizon repsonse for yourself.

MARCH 2019

TP-Link ignores a security problem

TP-Link 'smart' router proves to be anything but smart - just like its maker: Zero-day vuln dropped after silence
by Thomas Claburn of The Register   March 28, 2019
90 days ago Matthew Garrett, a Google employee, informed TP-Link of a bug in their all-in-one SR20 Smart Home Router. TP-Link ignored the problem. To me, this is the more important issue, much more interesting than the bug itself. Garret wrote: "I reported this to TP-Link in December via their security disclosure form, a process that was made difficult by the "Detailed description" field being limited to 500 characters. The page informed me that I'd hear back within three business days - a couple of weeks later, with no response, I tweeted at them asking for a contact and heard nothing back." The SR20 is a combination Zigbee/ZWave hub and router. Ignoring security problems is one of three mistakes TP-Link made. They also ship devices with debug daemons, software intended for testing, that does not belong in a released product. The software is the TP-Link Device Debug Protocol (tddp) and it has had multiple vulnerabilities in the past. This bug allows allows arbitrary command execution, as root, without authentication, from devices on the LAN. TDDP listens on the WAN side too, but the default firewall configuration blocks it there. To better control access to the router from LAN-side devices see the Local Administration section of my security checklist. Garrett also said that @CoreSecurity had the same experience when they reported TDDP flaws.


Bugs in two D-Link routers found by the BSI in Germany

D-Link investigates router vulnerability after German security agency warning
by CET news   March 1, 2019
D-Link is investigating bugs in the DIR-825 and DIR-878 after a warning from the German Federal Office for Information and Security (BSI). The BSI assigned a severity rating of "high". The bugs allow attackers to bypass the logon processes and execute malicious code. The bugs are easily exploited. The DIR-825 got its last update in 2015, the DIR-878 was last updated in August 2018. My guess (time will tell) is that these bugs will not be fixed.


Can Cisco be trusted?

Multiple vulnerabilities in Cisco Identity Services Engine (Unauth XSS to RCE as root)
by Pedro Ribeiro of Agile Information Security and Dominik Czarnota   First published Jan 20, 2019, Last Updated Feb 5, 2019
I don't care much about the details here, and the bugs are not in a router. But Cisco makes routers and the bigger issue, to me, is just how trustworthy Cisco is. They appear on this bug list often. Would you buy a router from them? Quoting: "ISE is distributed by Cisco as a virtual appliance. We have analysed version and found three vulnerabilities ... By putting them all together, we can achieve remote code execution as root, provided we can trap an administrator into visiting the page vulnerable to the stored cross site scripting." Agile dealt with Cisco about these bugs and it did not go well, leading to Ribeiro saying "These actions show Cisco is incredibly negligent with regards to the security of their customers. They are still shipping (and recommending) a product version vulnerable to unauthenticated remote code execution, with a fully working public exploit and no way to track fixes or fixed versions for these vulnerabilities." Ouch.

Three bugs in two Cisco routers

Cisco Small Business RV320 and RV325 Routers Information Disclosure Vulnerability
a Cisco Security Advisory   January 23, 2019
This happened fast. In September 2018, three bugs were reported to Cisco by German security firm RedTeam Pentesting. Cisco released patches for the bugs on January 23, 2019. The next day, proof of concept software was released that exploited the bugs. The day after that, bad guys were scanning for vulnerable Cisco routers. The bugs are exploitable on both the LAN and WAN side using just HTTP and/or HTTPS GET requests. The first two bugs expose information about the router to anyone who asks - no password is needed. One of these bugs exposes the Admin password. With that, bad guys can abuse the third bug to run any Linux command on the box. The vulnerable URLs are   and
where is either the LAN side or WAN side IP address of the router. The bugs are CVE-2019-1653 and CVE-2019-1652. The Cisco RV320 and RV325 routers are popular among both ISPs and large enterprises. On the WAN side, the web interface is exposed on TCP port 8007. Information about attacks on these bugs is on the News page.

Many Cisco switches have a backdoor account

Critical, Unpatched Cisco Flaw Leaves Small Business Networks Wide Open
by Tara Seals of Threatpost   January 18, 2019
These Cisco Small Business switches are vulnerable to full remote takeover thanks to a backdoor account: the 200 and 250 Series Smart Switches, the 300 and 350 Series Managed Switches, the 350X, 500 and 550X Series Stackable Managed Switches. There is no patch, but there is a work-around. The most interesting question is whether this is a bug or a feature. It looks like a bug in that it has an official CVE number (CVE-2018-15439) and a critical base CVSS severity rating of 9.8 (really bad). The devices ship with an in-built privileged user account that is used for the initial login. This account can not be removed. It is defined in a software-internal data structure and its not visible in either the running configuration or the startup configuration of an affected device. Bad guys can use this account to log in to a vulnerable device and execute commands with full admin privileges. The work-around is creating a user account with access privilege level of 15 (or higher?). But, if that account gets deleted, the hidden one works again, without notifying system administrators. It sure feels like a back door that can be easily hidden in case the virtual cops are coming. Why else hide the existence of this in-built account? Also, there have been many other backdoors discovered in Cisco software over the last year or so. It has been about 3 months and still no patch.



Two critical bugs in Synology routers

Synology Security Advisories
by Synology December 26, 2018
Bug Synology-SA-18:65 SRM: "A vulnerability allows remote attackers to execute arbitrary code via a susceptible version of Synology Router Manager (SRM)." No details are given. The bug was found by Uriya Yavnieli of VDOO. There is a fix for SRM 1.2 only, earlier versions of SRM are not addressed. The fix was released Dec 26th in firmware version 1.2-7742-5.
Bug Synology-SA-18:62 is in Netatalk versions prior to 3.1.12. The bug allows remote unauthenticated attackers to execute arbitrary code. The bug allows an out of bounds write in dsi_opensess.c due to the lack of bounds checking. This is also fixed in SRM 1.2 version 1.2-7742-5, same as the other bug.

Multiple D-Link routers disclose passwords

[CVE-2018-18007] atbox.htm on D-Link DSL-2770L devices allows remote unauthenticated attackers to discover admin credentials
by Tyler Cui   Dec 16, 2018
The buggy device is the D-Link DSL-2770L, a DSL modem/router. The bug: "An authenticated user can visit the page atbox.htm, for example, http://victim_ip/atbox.htm, and obtain clear text password of user admin at the line: else if(ff.curpd.value != '__password__') location='atbox_pd.htm' "
Disgraceful coding by D-Link. No excuse for this at all. Also coming down the pike:
CVE-2018-18008: This vulnerability affects D-Link DSL-2770L, DIR-140L, DIR-640L, DWR-116, DWR-512, DWR-555, and DWR-921 routers. An unauthenticated user can visit the page 'spaces.htm' and obtain the admin account password in clear text
CVE-2018-18009: This vulnerability affects D-Link DIR-140L and DIR-640L routers. A remote unauthenticated user can access the file 'dirary0.js' and obtain the admin account password in clear text.
The bug descriptions all say both that the attacker has to be authenticated and that the attacker does not have to be authenticated. It is not clear if these bugs can be exploited remotely or not. D-Link was notified of the bugs in June 2018 and never created a patch. The pattern is clear. This programming bug is so bad, really so amateurish, that avoiding D-Link devices altogether seems the smart thing to do.

High end Huawei routers leak password information

Information Disclosure Vulnerability CVE-2018-7900 Makes It Easy for Attackers to Find Huawei Devices at Risk
by Ankit Anubhav of NewSky Security   December 19, 2018
Simply put, everyone is at fault. Huawei for creating the vulnerability and the companies running Huawei routers for using default credentials. Thanks to bug CVE-2018–7900 bad guys can tell if a Huawei router is using the default password without even trying to logon to the router. All they need do is examine the HTML for the logon page. Even easier, ZoomEye and/or Shodan search engines can, if you know what to look for, report all Huawei routers using default credentials. The problem was reported to Huawei in Sept. 2018 and they have issued a patch. The vulnerable routers are high end devices used by ISPs and the patch has not yet been installed everywhere. Which specific routers are vulnerable was not disclosed.

Three buggy Trendnet routers will not be fixed

Multiple vulnerabilities found in Trendnet routers and IP Cameras
by Prashast Srivastava, Mathias Payer, Howard Shrobe and Hamed Okhravi   December 7, 2018
The bugs are in these TRENDnet routers: TEW-634GRU, TEW-673GRU and TEW-632BRP. Two IP cameras were also buggy. For all the flaws, it is not clear if they can be exploited remotely or not. One flaw requires the attacker to already be logged in to the router, but another one does not require any authentication. One flaw makes it possible to execute arbitrary commands on the router with root privileges. The routers are old (End of Life) and will not be patched.


Four bugs in the TP-Link TL-R600VPN

From directory traversal to direct travesty: Crash, hijack, siphon off this TP-Link VPN box via classic exploitable bugs
by Richard Chirgwin of The Register   November 20, 20189
Cisco's Talos found four security vulnerabilities in the TP-Link TL-R600VPN router. A denial-of-service flaw and a file-leaking bug are both due to input sanitisation mistakes. The directory traversal bug lets anyone read any file on the system. Parsing bugs led to two remote code execution (RCE) flaws that can be exploited by a logged-in user. However, the other two flaws can be exploited by anyone that can access the web interface. Definitely exploitable on the LAN side, and if remote administration is enabled, then exploitable on the WAN side too. The article said that fixes are available, but that does not seem to be true. On March 29, 2019 I found the newest firmware for the vulnerable hardware versions 2 and 3 to have been released in August 2016 and August 2014, well before these bugs were found.

A bug in an old D-Link router

CyRC analysis: CVE-2018-18907 authentication bypass vulnerability in D-Link DIR-850L wireless router
by the Synopsys Cybersecurity Research Center   November 15, 2018
The D-Link DIR-850L router was initially released in early 2013. Hardware version A (there is also a B) has a bug that lets attackers get onto its Wi-Fi network with having to know the WPA2 password. D-Link issued a patch three months after the bug was first reported. The only router tested for this flaw was the DIR-850L which Amazon is currently selling (in the US) for $60. No one has said anything about whether similar models might also be affected. Seems like no one has bothered testing other models. The model in question was chosen at random, the researcher was looking into something unrelated and just happened to have this particular router available to him. So, it is quite possible that other D-Link routers are also vulnerable. And, speaking of D-Link, lets not forget that the Federal Trade Commission (FTC) filed a lawsuit against D-Link early in 2017 complaining of assorted bad security practices. There will be a trial in January 2019. On a related note, I tried to view the tech support page for the DIR-850L router but it would not load in my browser. D-Link uses TLS 1.0 on their tech support site. This is a very old and known buggy protocol and I had disabled its use in my browser.

Is this a good thing?

Cisco removed its seventh backdoor account this year, and that's a good thing
by Catalin Cimpanu for ZDNet   November 7, 2018
For the seventh time this year, Cisco has removed a backdoor account from one of its products. Five of the seven were discovered by Cisco's internal testers. The company has been reviewing the source code of all of its software since December 2015. In an attempt to make George Carlin proud, Cisco refers to backdoor accounts as "undocumented, static user credentials for the default administrative account" or "the affected software enables a privileged user account without notifying administrators of the system."

Bugs in Xiaomi Mi Router 3

Hack Routers, Get Toys: Exploiting the Mi Router 3
by Shaun Mirani of Independent Security Evaluators   November 6, 2018
There are three bugs in the Xiaomi Mi Router 3 running firmware version 2.22.15. Two are command injection flaws, the third is reflected XSS. The command injection flaws allow an authenticated user to run arbitrary system commands with root privileges. The bugs were reported to Xiaomi in June. And, that's where it ends. The article is, frankly, amateurish. It does not say if the flaws are exploitable on the LAN side, the WAN side or both. It does not say if the XSS flaw can be exploited by an un-authenticated user. It does not say anything about fixes from Xiaomi.

Bleeding Bit bug in high end Access Points

Bluetooth bugs bite millions of Wi-Fi APs from Cisco, Meraki, and Aruba
by Dan Goodin of Ars Technica   November 1, 2018
Yes, the bugs are in Access Points and not routers. Yes, the bugs are in high end enterprise devices rather than consumer routers. So, why is it included here? I felt like it. Millions of Wi-Fi access points sold by Cisco, Meraki, and Aruba a critical Bluetooth bug that could allow attackers to run install and run malware on the devices. The bug was found by Armis. The malware could get access to all subnets, that is, it would not be stopped by a VLAN. The bug is in Bluetooth Low Energy (BLE), in software from Texas Instruments and they were aware of the issue, but they were not aware that it could be exploited in such a malicious manner. Why would a Wi-Fi Access Point support Bluetooth in the first place? Fancy features. Retailers can use them to track customers inside stores by monitoring the Bluetooth beacons sent by smartphones. Not me, Bluetooth is always disabled on my phone. Meraki and Aruba have issued patches. The real-world likelihood of this being exploited is debatable. BLE is enabled by default on some, not all, vulnerable Cisco and Meraki APs. Also, the bug requires a scanning feature to be enabled and it is disabled by default on all vulnerable devices.
A second bug has to do with an over-the-air firmware update feature of Aruba APs. The feature exists to ease firmware updates while developing products. It was never intended to be included in production devices. But, Aruba makes a password-protected version of the update feature available in their series 300 APs. Password? Smashword. The password used across all the devices is identical. Way to go Aruba. An attacker can learn the password by sniffing a legitimate update or reverse-engineering the device. Game over. Bad guys can then install any firmware they want.
Tin foil hat: a reader comment at Ars raised an issue that I first heard at a security conference this past summer. What if the removal of 3.5 mm audio ports in phones was to force more people to keep Bluetooth enabled, and thus, keep them traceable? If that is true, we won't know for at least 30 years.


Yet another ISP behaving badly

We asked 100 people to name a backdoored router. You said 'EE's 4GEE HH70'. Our survey says... Top answer!
by Chris Williams of The Register   October 26, 2018
A Wi-Fi router (4GEE HH70 gateways) used by British mobile network EE has a hidden backdoor account with a hard-coded username and password. The account is accessible via SSH from the LAN (inside) side of the router. The devices run OpenWRT and the account is root. The 4GEE home gateway connects to EE's mobile phone network. They are used by people who live in rural areas without fast wired connectivity. When the problem was reported to EE they blew it off, until The Register got involved. That said, it was still not clear whether a patch had been rolled out or not. After shaming EE, The Register learned that they did issue a patch, but customers have to install the new firmware themselves.

New Cisco flaw

Cisco zero-day exploited in the wild to crash and reload devices
by Catalin Cimpanu for ZDNet   October 31, 2018
Cisco has revealed the existence of a zero-day vulnerability affecting products that run Adaptive Security Appliance and Firepower Threat Defense software. The flaw allows an unauthenticated, remote attacker to cause a device to reload or trigger high CPU usage, resulting in a denial of service. The vulnerability resides in the Session Initiation Protocol (SIP) inspection feature. The vulnerability has been exploited in the wild. There is not yet a patch available, but there are mitigations, the most obvious being to disable SIP inspection. Another defense is to block the bad guys IP address (pretty lame). Finally, in the attacks seen to date, the "Sent-by Address" has been all zeros, so these can also be filtered. Known vulnerable devices are: 3000 Series Industrial Security Appliance, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance, Firepower 2100 and 4100 Series Security Appliance, Firepower 9300 ASA Security Module and FTD Virtual.
Nov. 6, 2018: Still no patches released.

Krack is back - new Wi-Fi issues get no press coverage

Auditing KRACKs in Wi-Fi
by Mathy Vanhoef of imec-DistriNet, KU Leuven   September 2018
Last year we had the Krack vulnerability in WPA2 and everyone fixed it, or so we thought. In certain cases, attacks are still possible according to newly published research from Mathy Vanhoef and Frank Piessens. Vanhoef discovered the flaw initially. They report on three problems. First, buggy bug fixes. Second, they discovered new techniques to bypass the official defense against KRACK, allowing an attacker to replay broadcast and multicast frames. However, they do say that this can only be abused to reinstall the (integrity) group key, and it is non-trivial to execute in practice. Third, they disclosed easier and more effective techniques to attack unpatched Wi-Fi devices. And, for good luck, they explain in more detail how to abuse certain vulnerabilities that were disclosed last year. The tech press has ignored this, perhaps because they write that " most users should not worry ... our new paper and results are not as serious as the original key reinstallation attacks."
Still, they inspected patches and open source code and shamed Apple: macOS was found to re-use the SNonce during rekeys of the session key (this is beyond me) and iOS did not properly install the integrity group key (beyond me too). They write that these bugs have a similar impact as the original KRACK attacks. And, Apple never owned up to their mistake. Their patches to their patches are not mentioned in Apple's security update notes. Their tests showed that the code is finally correct in iOS 12.0 and macOS High Seirra 10.13.3 (maybe earlier).
In addition, some Wi-Fi devices accept replayed message 4's of the 4-way handshake. They cited more than 100 devices (routers, APs, wireless cameras, wireless network extenders, home automation switches, NAS devices and smart power plugs) that use the MediaTek MT7620 chip, such as the Asus RT-AC51U router as being vulnerable. An attacker can abuse this to trivially trigger key re-installations against the router, without having to be a man-in-the-middle. This makes it possible to decrypt, replay, and possibly forge frames. MediaTek has promised a fix sometime in the future.
Looking forward, they note that WPA3 does not prevent key re-installation attacks because it still uses the 4-way handshake (in combination with the new Dragonfly handshake). Any particular implementation of the 4-way handshake may be vulnerable to KRACK.

Bugs in Linksys E Series routers

Vulnerability Spotlight: Linksys E Series Multiple OS Command Injection Vulnerabilities
by Cisco Talos   October 16, 2018
Three vulnerabilities are confirmed in multiple Linksys E Series wireless routers with various firmware versions. Exploiting these vulnerabilities requires the attacker to have already authenticated with the device. Still, they do allow a bad guy to obtain full control over a router, which would then allow for the installation of malicious code. Which models? The only ones mentioned are the E1200 and the E2500 both of which have patches available. The vulnerability state of other E Series routers is not clear (to me at least).

Another huge security flaw for Cisco

libssh Authentication Bypass Vulnerability Affecting Cisco Products: October 2018
by Cisco   October 19, 2018
Quoting "A vulnerability in libssh could allow an unauthenticated, remote attacker to bypass authentication on a targeted system. An attacker could exploit this vulnerability by presenting a SSH2_MSG_USERAUTH_SUCCESS message to a targeted system. A successful exploit could allow the attacker to bypass authentication and gain unauthorized access to a targeted system." Cisco is currently investigating which products are vulnerable.

D-Link shows how much they care about security

Last year, D-Link flubbed a router bug-fix, so it's back with total pwnage
by Richard Chirgwin of The Register   October 17, 2018
First sentence: "Eight D-Link router variants are vulnerable to complete pwnage via a combination of security screwups, and only two are going to get patched." Just this one sentence is enough to make a thinking person avoid D-Link routers. D-Link was notified of these bugs in May 2018 and has, to date, done nothing. Eight devices are known vulnerable. Six of them will not get fixes because D-Link deems them too old to bother with. They are: DWR-140, DWR-512, DWR-640, DWR-712, DWR-912 and DWR-921. D-Link has said they will fix the DWR-116 and DWR-111 but after all this time, they have not done so. The bugs, found by Błażej Adamczyk include storing passwords in plaintext, yet another indicator of how much D-Link cares about security. One person does not have access to an entire product line, so it is likely that other D-Link routers which the researcher could not test are also vulnerable.

Still more MikroTik bugs

Tenable Research Advisory: Multiple Vulnerabilities Discovered in MikroTik's RouterOS
by Jacob Baines of Tenable   October 7, 2018
Frankly, I can't keep up with the bugs in MikroTik devices. Suffice it to say, that owning a MikroTik device dooms you to a life of constant patching. The four bugs that Baines found are: an authenticated remote code execution (CVE-2018-1156), a file upload memory exhaustion (CVE-2018-1157), a www memory corruption (CVE-2018-1159) and a recursive parsing stack exhaustion (CVE-2018-1158). The first one is the most critical as it allows for full system access. The bugs exist in RouterOS 6.42.3, released in May 2018. The bugs are patched in RouterOS version 6.40.9 (released Aug 20, 2018), version 6.42.7 (released Aug 17, 2018) and version 6.43 (released Sept. 6, 2018). And, there is more too.
Baines presented his research Oct 7, 2018 at the DerbyCon conference in Kentucky. He disclosed that RouterOS has a somewhat hidden developer backdoor account and he was not the first person to discover it. Moreso, he expanded the exploitation of a previously disclosed path traversal vulnerability, CVE-2018-14847. His new approach let him extract the admin password and create an "option" package to enable the developer backdoor. Thus, a bad guy can connect to Telnet or SSH using the root user "devel" (the back door account) with the admin password. Mikrotik patched the path traversal bug in April 2018. However, it was not previously disclosed that the bug could be leveraged to write files. He created an exploit for Winbox, a Windows GUI application for MikroTik’s RouterOS software. MikroTik created their own encryption and their own protocol for talking to their RouterOS system. Baines and others have figured out the protocol. A recent scan by Tenable Research showed that only 30 percent of vulnerable devices have been patched.


Multiple bugs in TP-Link Wi-Fi Extenders

From Bad to Worse: Firmware Vulnerability Detection with the Centrifuge Platform
by Craig Heffner of Refirm Labs   August 13, 2018
This story starts with a command injection vulnerability published for the TP-Link WL-WA850RE Wi-Fi Range Extender. The bug grants a remote attacker complete access to the device, but it requires administrative credentials. Using software from his company, the Centrifuge Platform, Heffner found a more serious bug that allows a remote attacker to completely control the device even without prior knowledge of the administrative credentials. The vulnerability affects multiple TP-Link products, including devices connected to the Internet and therefore susceptible to remote attack. At first, Heffner found tons of calls to strcpy with stack addresses as the destination. Then he put the httpd binary into a disassembler. In the previously known bug, the wps_setup_pin value can be used to exploit both a stack-based buffer overflow and command injection. But, the vulnerable code sits behind an authentication check. So, he looked for HTTP requests that do not require authentication. He got a list of 24 function handlers that do not require authentication. The most interesting one was: /fs/data/config.bin which generates the backup configuration file. Yes, an un-authenticated user can dump a file with the admin password. The config file is compressed and DES encrypted. But, TP-Link has been re-using the same encryption key for years. After decrypting the config file, Heffner found the admin password was stored as an MD5 hash which can be directly fed into the web interface of the router. Attackers do not need to know the plain text password. Heffner wrote: "Thanks to vendor code reuse, bugs like these are rarely isolated to a single product (or even to a single OEM!)." So, he went looking for other TP-Link products that might be affected, again using software from his company that scans firmware for known vulnerabilities. Other vulnerable range extenders are the: RE305, RE450, TL-WA830RE, TL-WA850RE and the TL-WA855RE. Heffner found many of these were directly accessible from the Internet. He developed a proof of concept exploit script that grabs the configuration file, decrypts it, decompresses it, authenticates to the target device, and exploits the command injection bug to start a telnet server on port 8080. It appears that little, if any, work has been done by either researchers or TP-LInk into whether other devices are affected by these bugs. TP-Link was told of all this but there are, as of now, no patches. It is not clear if they responded to Heffner at all.

New IKE VPN flaw affects Cisco, Huawei and others. Patches available.

Cisco Patches Its Operating Systems Against New IKE Crypto Attack
by Catalin Cimpanu of Bleeping Computer   August 13, 2018
Any Cisco IOS or IOS XE device that is configured with the "authentication rsa-encr" option is vulnerable to a newly discovered attack on IKE. The Cisco IOS XR operating system is not affected. The bug stems from the fact that the software responds incorrectly to decryption failures. The bug lets bad guys attack the first Phase of IKE and, if successful, attackers are able to impersonate another IPsec endpoint or be an active man-in-the middle. It is not possible to recover data from an already established IPsec session. The attack also works against the IKEv1 implementations of Huawei, Clavister and ZyXEL. All companies were previously informed and issued patches.

New attack on WPA/WPA2 networks enabled for roaming

New attack on WPA/WPA2 using PMKID
by Atom   August 4, 2018
"This attack was discovered accidentally while looking for new ways to attack the new WPA3 security standard ... The main difference from existing attacks is that in this attack, capture of a full EAPOL 4-way handshake is not required. The new attack is performed on the RSN IE (Robust Security Network Information Element) of a single EAPOL frame. At this time, we do not know for which vendors or for how many routers this technique will work, but we think it will work against all 802.11i/p/q/r networks with roaming functions enabled (most modern routers). The main advantages of this attack are as follow:
No more regular users required - because the attacker directly communicates with the AP (aka "client-less" attack)
No more waiting for a complete 4-way handshake between the regular user and the AP
No more eventual retransmissions of EAPOL frames (which can lead to uncrackable results)
No more eventual invalid passwords sent by the regular user
No more lost EAPOL frames when the regular user or the AP is too far away from the attacker
No more fixing of nonce and replaycounter values required (resulting in slightly higher speeds)
No more special output format (pcap, hccapx, etc.) - final data will appear as regular hex encoded string "

JULY 2018

Huge bug in Juniper's Junos OS

Security Bulletin: Junos OS: A privilege escalation vulnerability exists where authenticated users with shell access can become root (CVE-2018-0024)
by Juniper   July 11, 2018
This is a doozy. An authenticated unprivileged attacker can gain full control of the system thanks to an Improper Privilege Management vulnerability in a shell session. The flaw is in multiple versions of the OS: 12.1X46, 12.3, 12.3X48, 14.1X53, 15.1X49. Affected platforms: EX Series, QFX3500, QFX3600, QFX5100, SRX Series. This issue was found during internal product security testing or research. Fixes have been released. This was but one of a large number of bug fixes just released by Juniper. See their Security Advisories page for the rest.

After 2 years, 3 bugs in ADB hardware finally fixed

Year-Old Critical Vulnerabilities Patched in ISP Broadband Gear
by Tom Spring of Threatpost   July 5, 2018
In June of 2016, SEC Consult Vulnerability Lab identified three critical bugs in Switzerland-based ADB routers and gateways. Here we are, two years later and the bugs are finally being publicly disclosed and fixed. ADB manufactures hardware for over two dozen communications firms, including Cox Communication and Charter Communications in the US. Bug 1 is a local root jailbreak that can be exploited thanks to a network file sharing flaw. It lets an attacker get full access to the device with highest privileges. Oopsie. Bug 2 lets an attacker access device settings otherwise forbidden to the user. Manipulated settings, might, for example, turn on the Telnet server even if the ISP had disabled it. Bug 2 requires the bad guy to have a user account, but the default account from the ISP or printed on the device, would suffice. Bug 3 is a privilege escalation flaw via Linux group manipulation. It can grant an attacker access to the command line interface, even if it was previously disabled by the ISP. Every CLI is not the same, but the CLI might offer access to all the configuration settings. All the bugs now have patches available, for those that know to look for them. Neither Cox nor Charter returned Threatpost inquiries on if or how many of their customers may have been impacted by the vulnerabilities. Of course not, the fewer customers that know about this the better.

JUNE 2018

Netgear fixes many bugs

Netgear Security Advisories
by Netgear   June 22, 2018
As before, another case of the glass being half empty or half full. Netgear has fixed many bugs in their routers. At some point, however, you have to wonder if their routers are like Flash, a never ending source of bugs. Still, they do seem to make an honest effort to fix things, they are very public about the bugs, and they have a security newsletter announcing their bug fixes, so give them credit for that. The patches are:
6/22/2018 Security Advisory for Denial of Service on Some Routers, PSV-2017-3168
6/22/2018 Security Advisory for Denial of Service on Some Routers, PSV-2017-3169
6/22/2018 Security Advisory for Sensitive Information Disclosure on GS810EMX, PSV-2018-0220
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Routers, PSV-2017-3166
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Gateways and Routers, PSV-2017-3160
6/22/2018 Security Advisory for Post-Authentication Command Injection on Some Gateways and Routers, PSV-2017-3159
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Gateways and Routers, PSV-2017-3158
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Gateways and Routers, PSV-2017-3157
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Gateways and Routers, PSV-2017-3156
6/22/2018 Security Advisory for Post-Authentication Stack Overflow on Some Gateways and Routers, PSV-2017-3155
6/22/2018 Security Advisory for Post-Authentication Buffer Overflow on Some Gateways and Routers, PSV-2017-3154
6/22/2018 Security Advisory for Post-Authentication Command Injection on Some Gateways and Routers, PSV-2017-3152
6/22/2018 Security Advisory for Pre-Authentication Buffer Overflow on Some Gateways, Routers, and Extenders, PSV-2017-3136
6/22/2018 Security Advisory for Post-Authentication Command Injection on Some Gateways and Routers, PSV-2017-3133
6/22/2018 Security Advisory for Stored Cross-Site Scripting on Some Gateways and Routers, PSV-2017-3101
6/21/2018 Security Advisory for Post-Authentication Buffer Overflow on Some Gateways, Routers, and Extenders, PSV-2017-2460
6/21/2018 Security Advisory for Post-Authentication Command Injection on Some Gateways and Routers, PSV-2017-2248
6/21/2018 Security Advisory for Security Misconfiguration on Some Gateways and Routers, PSV-2017-0429
6/14/2018 Security Advisory for Pre-Authentication Command Injection on Some Gateways, Routers, and Extenders, PSV-2016-0074

Cisco has some serious explaining to do

Cisco Removes Backdoor Account, Fourth in the Last Four Months
by Catalin Cimpanu of Bleeping Computer   June 8, 2018
For the fourth time in as many months, Cisco has removed hardcoded credentials that were left inside one of its products. This hardcoded password was found in their Wide Area Application Services (WAAS). WAAS is WAN traffic management. software that runs on Cisco hardware. Calling it a password is a bit off, there was a hardcoded, read-only SNMP community string in the configuration file of the SNMP daemon. Anyone knowing the string can retrieve stats and system info from affected devices. Again, anyone can abuse this, all you needed to know is the character string. It provides stats and system information via SNMP. This was a very well hidden secret, which has to make anyone wonder how it came to be. The existence of the secret SNMP community string was hidden from device owners. It was even hidden from people with an admin account on the device. Go figure. It was discovered by Aaron Blair from RIoT Solutions as he was researching a different bug. The second bug elevated a normal admin account to root access and once a root user, he could see the secret SNMP string. The hidden string was just removed.

More Cisco bugs

Cisco Patches Critical Flaws in IOS XE and Prime Collaboration Provisioning
by Lucian Constantin June 8, 2018
These are bad. IOS XE is the Cisco operating system for networking devices such as routers. It has a critical flaw in its authentication, authorization and accounting (AAA) security services. The bug is due to incorrectly parsing usernames during the authentication process. It can be exploited by unauthenticated, remote attackers to execute arbitrary code on the affected devices. Yikes. They also fixed a critical vulnerability in PCP (Prime Collaboration Provisioning). An open TCP/IP port in the Network Interface and Configuration Engine (NICE) service, gave attackers access to the Java Remote Method Invocation (RMI) system. This, in turn, let bad guys perform malicious actions. In addition to these critical bugs, Cisco fixed five other high-risk flaws in PCP this week. And, they fixed high-risk bugs in their Web Security Appliance; Identity Services Engine; Network Services Orchestrator; IP Phone 6800, 7800 and 8800 Series; Cisco Meeting Server and Adaptive Security Appliance. Bugs bugs bugs.

Critical bug in Cisco ACS has been fixed

Cisco fixes critical bug that exposed networks to hackers
by Zack Whittaker for ZDNet June 7, 2018
Technically, not a router bug, but from Cisco and network related. A critical bug in the Cisco Secure Access Control System (ACS), which system administrators use to authenticate users across a network, could have allowed hackers to remotely break into corporate networks. The bug was reported to Cisco by Positive Technologies. An attacker exploiting the bug could gain near-unfettered access to a network, including control of routers and firewalls. This, in turn, could allow interception and modification of network traffic and grant access to closed-off sensitive areas of a network. The bug was fixed in May 2018. ACS reached end-of-life in 2017.

MAY 2018

VPNFilter - a very big deal

VPNFilter router malware - just the bad stuff
by me   June 4, 2018 (last updated June 8th)
VPNFilter is both malware and a botnet. It infects routers from Linksys, MikroTik, Netgear, TP-Link, ASUS, D-Link, Huawei, Ubiquiti, UPVEL and ZTE. It also was found on NAS devices from QNAP. For the most part we do not know the bugs in each router that the malware exploited. However, everything that has come out in the first two weeks after the initial announcement, points to the bad guys exploiting known bugs. No zero day flaws were needed. Most of my coverage is on the News page.

Comcast leaks customer Wi-Fi passwords and network names

Comcast website bug leaks Xfinity customer data
by Zack Whittaker for ZDNet   May 21, 2018
Technically, this is not a router bug, but it's close enough. The Comcast website (, which was/is used by customers to set up their home services, could be hacked to display a customers home address, Wi-Fi network name (SSID) and Wi-Fi password. And, not just display, an attacker could also change the SSID and/or Wi-Fi password. But, the issue was only for customers using equipment from Comcast. Those with their own routers were safe. An attacker only needed to provide the customer account number and their house or apartment number. If you lived at 123 Main Street, all the attacker needed to know was 123. Comcast claimed they fixed the problem, but we have no idea how long this vulnerability existed. For more on why not to use a router from any ISP see the ISP routers page.

Bug in old D-Link DSL gateways was never fixed, now being abused

Widely used D-Link modem/router under mass attack by potent IoT botnet
by Dan Goodin of Ars Technica   June 20, 2018
Bad guys are exploiting a bug in very old D-Link DSL-2750B DSL gateways in an attempt to make them part of the Satori botnet. The bug has been known for roughly 2 years but the devices have been abandoned by D-Link and the ISPs that gave them out. If you have such a device, it needs to be replaced. This is yet another reason to not use any hardware from your ISP, when possible. The bug allows remote command execution without any authorization needed. The vulnerability can be exploited using the "cli" parameter that directly invokes the "ayecli" binary. It is also possible to retrieve the admin password, wifi password, etc. Also covered in the Router News page.

D-Link caught with poor security, yet again

Backdoors in D-Link's backyard
by Denis Makrushin of Kaspersky SecureList   May 23, 2018
Round up the usual suspects. Yet another D-Link router is vulnerable to hacking. Kaspersky researched the DIR-620 router because it is a common router given out by ISPs. Most importantly here is that "The firmware runs on various D-Link routers" so anyone with a D-Link router should consider replacing it. Especially, old D-Link routers, as the company has refused to fix these problems because they deem the router too old to bother with. Kaspersky notes that it is not possible to count the number of vulnerable routers because "most home routers are located behind their ISP’s NAT." Kaspersky found two bugs and two hard coded backdoor accounts, one for Telnet, the other for access to the web admin interface of the router. Interestingly, the backdoor credentials contain the name of the ISP in the login string, so it is impossible to know if the ISP or D-Link is to blame. Owners of the routers can not do anything about the hard coded account for the web interface. They can't see it or delete it. Kaspersky did not discuss local admin access vs. remote access. One of the bugs lets attacker recover Telnet credentials. Another flaw lets attackers execute OS commands via parameters of an admin page's URL. The last is a reflected cross-site scripting bug in the "Quick Search" field of the router's web interface. Most of the routers were deployed by Russian, CIS, and Eastern European ISPs to their customers. The vast majority of these devices are located in Russia.

Talk Talk routers vulnerable to WPS pin code attack - 7 years after it became public

ISP TalkTalk's Wi-Fi passwords Walk Walk thanks to Awks Awks router security hole
by Shaun Nichols of The Register   May 22, 2018
Talk Talk is a British ISP and telco. Their "Super Routers" have been confirmed vulnerable to the classic WPS pin code attack, first seen back in 2011. You can't make this stuff up. The flaw was discovered by a company called IndigoFuzz using a Windows program called Dumpper that is available on Sourceforge. You have to be within Wi-Fi range to attack a vulnerable router. Some routers can disable WPS, but neither article mentioned if the Talk Talk routers can do so. Also, neither article mentioned that a router that has been hacked via WPS will remain available to the attacker even if the Wi-Fi password is later changed and even if the Wi-Fi password is very long. WPS is a back door. Note that the WPS pin code attack has nothing to do with the WPS pairing button. WPS supports multiple modes of operation.

Bug in DrayTek routers is being both exploited and fixed

High-end router flinger DrayTek admits to zero day in bunch of Vigor kit
by Kat Hall of The Register   May 21, 2018
Quoting: "DrayTek routers are considered high end in the UK - retailing at around 200 pounds, more than twice the price of garden-variety alternatives - and are mostly used by businesses." It seems that buyers are getting their moneys worth. Yes, the routers have a bug, but the report of the flaw came from DrayTek themselves, which is quite rare. They also released an advisory about the problem that was unusually frank and helpful. Many of the known buggy routers have new firmware that fixes the problem, others will shortly have new firmware. The company also lists devices that are not buggy at all. Firmware updates have to be manually done, the routers do not self-update. For obvious reasons, they have not released any technical details of the flaw. Bad guys have been using the flaw to change the DNS servers in the routers, an old tried and true attack. On the home page of this site (in the ongoing defense section) I recommend being aware of your DNS servers. The resources page lists many websites that report on currently used DNS servers. No articles about this mentioned that these sites exist.

Glass half full or half empty for Cisco devices?

Hardcoded Password Found in Cisco Enterprise Software, Again
by Catalin Cimpanu of Bleeping Computer   May 17, 2018
Cisco just released 16 security advisories that warned about 13 boring bugs and 3 critical ones. The worst (CVE-2018-0222) is a hard coded backdoor account or, to use words from a PR firm - "undocumented, static user credentials for the default administrative account." The hard coded password gives those in the know root access. The other two critical flaws are both bypasses of the authentication system for Cisco Digital Network Architecture (DNA) Center software. The flaws were uncovered by an internal audit. Back in 2015, after a backdoor account that could decrypt VPN traffic was found in Juniper software, Cisco decided to audit their code. And ... "The company discovered many backdoors and hardcoded accounts in the past two years as part of internal audits..."

Sierra Wireless routers were totally completely hackable

Sierra Wireless Patches Critical Vulns in Range of Wireless Routers
by Tara Seals of Threatpost   May 8, 2018
Sierra Wireless just patched two critical vulnerabilities for its wireless gateways that would leave the enterprise devices helpless to an array of remote threats. The most critical flaw allowed a remote attacker with no authentication whatsoever to execute arbitrary code on the routers and gain full control of a vulnerable device. Sierra Wireless has a footprint of more than 3 million AirLink devices. Vulnerabilities affect AirLink Gateways LS300, GX400, GX/ES440, GX/ES450, RV50, RV50X, MP70, MP70E. The article does not say how the company learned of the flaws. Technical details are not available because Sierra Wireless Tech Bulletins are only for their customers, not the general public.

ISP in Brazil ships routers without a password

5,000 Routers With No Telnet Password. Nothing to See Here! Move Along!
by Catalin Cimpanu of Bleeping Computer   May 10, 2018
Oi Internet, an ISP in Brazil has shipped their customers Datacom routers (models DM991CR, DM706CR, and DM991CS) with Telnet enabled and no Telnet password. The report comes from Ankit Anubhav, Principal Researcher at NewSky Security. He has detected 5,000 of the vulnerable routers. Worse than a house with the front door unlocked, these routers are a house without a front door at all. This illustrates why I consider a router from an ISP to be the least secure option. You are safer with an off-the-shelf consumer router, but better still, with a business class router.

APRIL 2018

Dasan GPON optical routers are buggy and tough luck

Critical RCE Vulnerability Found in Over a Million GPON Home Routers
by Sarit Newman of vpnMentor   No date
This strikes me as a scam. I suspect its a test of how gullible those covering technology are. For one thing, there is no date on the article. Then too, vpnMentor is not a security company. The author's qualification is that "she loves being organized." Bugs are found by people, the article only refers to "we". There are no links to the CVEs. I searched for each one and found that the two CVE numbers have been assigned to someone who has published nothing and not even identified themselves. Also GPON is a technology not a brand, as far as I can tell. That is, its Wi-Fi, not Linksys. The article did not mention one specific brand of router. All it said was "the routers are provided by ISPs" and it did not even mention one ISP by name. As to the details, vpnMentor claims that CVE-2018-10561 is a bug that lets attackers bypass authentication on the routers. They do not say if the authentication bypass lets only local attackers into the routers or also remote attackers. They also claim that CVE-2018-10562 is a command injection flaw that let them execute commands on the un-identified routers.
Update May 4, 2018: There is now some text describing the two CVE bug reports and it identifies the router manufacturer, Dasan of South Korea. And, it seems these bugs are now being exploited.
Update May 10, 2018: At least 5 botnets are competing to hack these Dasan routers. See the Router News page for more. Also, the routers are old and will not be patched. And, VPNmentor has released their own most un-official patch.
Update May 21, 2018: These same routers appear to have another zero day flaw that bad guys are exploiting. See GPON Routers Attacked With New Zero-Day by Catalin Cimpanu for Bleeping Computer.

How to hack MikroTik routers

by Dayton Pidhirney of Seekintoo   April 28, 2018
Most of this article is over my head, but it is clearly a detailed technical guide to hacking MikroTik routers. They appear to be quite hackable. The author is not impressed with the company's coding prowess. Quoting: "... a span of approximately four years elapsed since the vulnerability was introduced until the time it was fixed. Four years should be enough for multiple competent code reviews to catch a blatant integer overflow in a critical function like reading user POST data. The fact this small issue was not discovered and fixed for so long, leads myself and I'm sure others to believe MK doesn't do code reviews or does not complete them often. If you are reading this MK, maybe stop custom writing and maintaining your: Webserver, Samba Server, RADIUS server, SSH server, TELNET server, FTP server, etc. Clearly you can't."

TP-Link does not fix old buggy router

TPLink TLWR740n Router Remote Code Execution
by Tim Carrington of Fidus Information Security   April 26, 2018
In October 2017, Fidus reported on TP-Link having a pattern of bad coding that can result in the WR940N router being hacked. TP-Link fixes the WR940N router. Fidus wonders how come no one else had found the flaws as they were easy to find. Worse, TP-Link only fixes the WR940N. Later, Fidus finds the exact same bugging pattern of code in the TLWR740n router. They report the problem to TP-Link on Jan. 25, 2018. On March 29th, TP-Link sent Fidus beta firmware that fixed the problem. But, TP-Link never released the patched firmware. We have seen this pattern before with consumer routers - vendors only fix what the public knows about. The bigger issue here involves other TP-LInk routers. Which of them also have the same buggy code and thus are also vulnerable to the same attack? This is a great reason not to trust TP-Link.

Hard coded root account in ZTE routers

Hyperoptic router at risk of being hacked
by Andrew Laughlin of Which?   April 25, 2018
In October 2017, security firm Context Information Security found a flaw in ZTE routers used by British broadband ISP Hyperoptic. The ISP is fully fibre and specializes in super fast Internet. It is estimated that Hyperoptic has about 100,000 customers, mostly businesses. As of April 24, 2018 the flaw has been fixed and rolled out to all Hyperoptic customers. Dan Cater, Lead Security Consultant at Context, found the flaw, a combination of a hardcoded root account and a DNS rebinding vulnerability. As a result, simply clicking on a malicious link allowed bad guys to login to the ZTE routers will full, total control. The buggy devices are the H298N and H298A "HyperHub" routers. The fix includes new individual root passwords for every router. Just last week, the British National Cyber Security Centre (NCSC) warned UK telecoms and broadband operators not to use ZTE equipment for security reasons. None of the articles has any details on the flaw, but I suspect that changing the LAN side IP address of the router is a defense against this. So too changing the LAN side subnet and the port number used for Local Administration of the router.

UPnProxy- the UPnP abuse will never die - no progress in 5 years

UPnProxy: Blackhat Proxies via NAT Injections
by Akamai   Early April
UPnP is the router mis-configuration that will not go away. Back in January 2013 it was discovered that millions of routers were exposing UPnP on their WAN side (the Internet) by mistake. This report from Akamai found that 4.8 million routers are still doing so. They also found that bad guys are using this flaw/mis-configuration to treat routers as proxies as a way of hiding themselves online. My summary of this is on the News page.

MARCH 2018

A H-U-G-E number of Cisco bugs

March 2018 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication
by Cisco   Doc ID: ERP-66682   March 28, 2018
Cisco has released patches for 34 bugs, mostly to IOS and IOS XE. The bugs include three critical remote code execution flaws. To put this in perspective, Peplink has never released fixes for 34 bugs at once. They don't have that many bugs. One reason there were so many patches is that Cisco only releases bug fixes twice a year (March and September). This is a miserable way to maintain software. One critical flaw in IOS XE is an undocumented user account with a default username and password. An attacker could use this account to remotely connect to a vulnerable device. Just disgraceful. Another flaw is a remote code execution bug in the QoS subsystem of IOS and IOS XE. The problem is due to incorrect bounds checking of certain parameters sent to UDP port 18999. The bug that got press attention is in Smart Install. This should have been called Lazy Install. It is software for deploying new IOS and IOS XE switches and routers to a remote site while configure everything from headquarters. Smart Install was meant to make life easy for system administrators. As such, the Smart Install protocol does not require authentication. In Feb. 2017 Cisco warned about how insecure the Smart install Protocol was and suggested using their newer Network Plug and Play feature instead. Devices running the Smart Install client have TCP port 4786 open by default. Adding to the poor design is a bug - a stack-based buffer overflow enables an attacker to remotely execute arbitrary code without authentication. This is as bad as bad gets. Remote unauthenticated attackers can get full control of vulnerable devices. In all the time I have been following Peplink, they have never had one bug as severe as this. Since Smart Install was intended for internal use, at first, it was though this bug could only be exploited internally. But no. Embedi, the company that found the flaw, found 8.5 million devices that have the vulnerable port open on the Internet. Of those, only 250,000 were vulnerable to the flaw. The timeline here is shameful. Embedi discovered the flaw in May 2017. In September 2017 Cisco said they were still working on a fix and now, at the end of March 2018, it is finally released. These bugs were exploited a few days after the fixes were released. See the Routers in the news page for details.

New VPN client router Vilfo has poor security

Vilfo VPN router review
by Daniel Aleksandersen for his CTRL blog   March 20, 2018. (NOTE: vendor response is below)
Vilfo is a 5-person company about to launch a new VPN client router. Both the router and the company are offshoots of the Swedish VPN service provider OVPN. The hardware is high end and the software is based on OpenWRT/LEDE. A review by Daniel Aleksandersen found many security flaws in the design and operation. The problems start immediately with the initial setup. Quoting: "... the initial setup process in Vilfo's web administration interface happens over HTTP on an unencrypted WiFi connection that is literally broadcast in the clear to your neighborhood. You are required to input a lot of information in the web administration interface before you get the option to enable encryption on the connection. At the very least, you must provide the following: a unique license key for Vilfo, your email address, your username and password for at least one predefined VPN service provider, your desired username and administrative (root) password for the router, and at the end you also input your desired WiFi name and password. All of this information is transmitted in clear-text and can trivially be collected by nearby devices." Other security flaws:

Unauthenticated remote exploitation of MikroTik routers

MikroTik RouterOS SMB Buffer Overflow
by Core Security   March 15, 2018
MikroTik is a Latvian company that provides hardware and software for Internet connectivity in most of the countries around the world. RouterOS is their operating system based on the Linux v3.3.5 kernel. A buffer overflow was found in the RouterOS SMB service (Samba) when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and thus execute code on the system. The overflow occurs before authentication takes place, so it is possible for an unauthenticated remote attacker to exploit it. The flaw is CVE-2018-7445 and it was discovered by Juan Caillava and Maximiliano Vidal from Core Security Consulting Services. Version 6.41.3 of RouterOS contains a fix.

Seems like the UPnP bugs will never die

Inception Framework: Alive and Well, and Hiding Behind Proxies
by Symantec  March 14, 2018
First some background on the bad guys: "The cyber espionage group known as the Inception Framework has significantly developed its operations over the past three years, rolling out stealthy new tools and cleverly leveraging the cloud and the Internet of Things (IoT) in order to make its activities harder to detect ... The nature of Inception’s targets ... along with the capabilities of its tools, indicate that espionage is the primary motive of this group ... Blue Coat was able to determine that the attackers were communicating with through a hacked network of compromised routers, the majority of which were located in South Korea..." Then how they hide behind a chain of hacked routers: "Inception is continuing to use chains of infected routers to act as proxies and mask communications between the attackers and the cloud service providers they use. Certain router manufacturers have UPnP listening on WAN as a default configuration ... These routers are hijacked by Inception and configured to forward traffic from one port to another host on the internet. Abuse of this service requires no custom malware to be injected on the routers and can be used at scale very easily. Inception strings chains of these routers together to create multiple proxies to hide behind." This is the router bug that will not die. UPnP was never meant to be exposed to the Internet. Yet, back in January 2013, HD Moore, working for Rapid 7, found millions of routers doing just that. According to Symantec, Akamai reports 765,000 devices are currently vulnerable to this attack.

Cisco not immune to security problems

Hardcoded Password Found in Cisco Software
by Catalin Cimpanu of Bleeping Computer   March 8, 2018
As much as I advise against using consumer routers, high end devices from Cisco are also not immune to security problems. They just released 22 security advisories, including one that forced them to admit there was a hard coded password in their Prime Collaboration Provisioning software application. I don't know what that software does, but hard coding a password is a huge mistake and inexcusable (unless the US Government forced them to do this). Their other critical security flaw affected the Cisco Secure Access Control System, which was not as secure as it should have been. A Java deserialization issue allowed an unauthenticated, remote attacker to execute arbitrary commands with root privileges. Put another way, that's as bad as bad gets.


Dasan refuses to fix its buggy router

A potent botnet is exploiting a critical router bug that may never be fixed
by Dan Goodin of Ars Technica   Feb. 14, 2018
In October 2017 an independent researcher finds a bug in the Dasan Networks GPON ONT WiFi Router H640X . Specifically, the login_action function uses strcpy without checking the length of input from the client request. This creates a buffer overflow that can lead to remote code execution. It is not clear if the bug also exists in other Dasan devices. The researcher enlists SecuriTeam to contact Dasan. That does not go well, Dasan bascially ignores them. SecuriTeam publishes the details of the flaw in early December 2017. In early February 2018, Radware detects a new botnet where almost all the devices are from Dasant. They call it the Satori.Dasan botnet. Shodan reports about 40,000 devices listening on port 8080, with over half located in Vietnam. Satori infections don't survive a device reboot, so that's one defensive measure. If your router can set firewall rules, block which is the C and C server for the botnet.

Netgear has fixed multiple bugs including a doozy

Wish you could log into someone's Netgear box without a password? Summon a &genie=1
by Iain Thomson for The Register   February 9, 2018
Good news: Netgear fixed a lots of bugs affecting many of their routers. Bad news: lots of bugs, patching is a manual process that few router owners do and the flaws were found by Trustwave, not by Netgear.
-- The worst bug is vulnerable on the LAN side only, assuming Remote Administration is disabled. Anyone that can access the web-based configuration interface, can gain control of vulnerable routers without a password by simply adding "&genie=1" to the URL. The Security Checklist page has suggested ways to lock down LAN side access to a router (item 3). The flaw was discovered in March 2017 and the patch released in September 2017. 17 router models are affected.
-- Another flaw, in the genie_restoring.cgi script can be abused to extract files and passwords both from the router and from USB flash drived plugged into the router. 17 routers vulnerable here too. The flaw was discovered in March 2017 and the patch issued in August 2017.
-- A bug with WPS, leaves 6 Netgear routers vulnerable to arbitrary code execution as root for two minutes after the WPS button is pressed. This is due to a failure to sanitize hostnames. Simply put, if an attacker can press the WPS button on the router, the router can be completely compromised. This flaw was found in March 2017 and the patch was released in Oct. 2017.
-- The least serious flaw affects 6 routers. After logging in, root level command execution is possible via the device_name parameter on the lan.cgi page. Trustwave also found a three-stage attack leveraging three separate issues that lets any user connected to the router run OS commands as root on the device without providing any credentials.
-- See the October 2017 and November 2017 descriptions below of the bugs that Netgear fixed. Fixing bugs in a somewhat timely manner is good, but at some point you have to lose trust in their code base. And timely is a matter of opinion, these bugs took roughly 6 months to get fixed. Finally, the Netgear bug descriptions (here and here for example) say nothing at all about the nature of the problem. That does not inspire confidence.

Further proof that routers contain old software with known vulnerabilities

Comprehensive Firmware Binary Scan Finds KRACK is "Tip of Iceberg" For Known Wi-Fi Security Vulnerabilities
Press Release from Insignary February 6, 2018
In January 2016, the Wall Street Journal reported on home routers with old software containing known bugs - Rarely Patched Software Bugs in Home Routers Cripple Security. This report, from Insignary, shows that nothing has changed. Insignary does binary-level software composition analysis. In other words, they scan executable code (called firmware when dealing with routers) looking for signatures of open source software, and from those signatures, determine the version/release of the software in the executable code. In November 2017 they scanned the firmware of 32 Wi-Fi routers and found numerous known security vulnerabilities. No zero days here. The routers were from ASUS, Belkin, Buffalo, Cisco, D-Link, EFM, Huawei, Linksys, Netis and TP-Link. Every router had a security vulnerability. A majority of the examined firmware contained components with more than 10 "Severity High" security vulnerabilities. Half of the firmware had "Severity Critical" vulnerabilities. This report is, of course, a plug for their detection software, but that doesn't change the results.


Critical Cisco VPN bug is worse than originally thought, then patched badly

Cisco drops a mega-vulnerability alert for VPN devices
by Sean Gallagher of Ars Technica January 30, 2018
Cedric Halbronn of the NCC Group discovered a critical bug in Cisco network security devices and VPN software. Devices configured with WebVPN clientless VPN software are vulnerable to an attack that could bypass normal security and allow an attacker to gain full control of vulnerable devices. That's bad. WebVPN allows someone to connect to a corporate intranet using just a secure web browser session. It requires no VPN client software or certificate. The attack on the VPN server is done with specially formatted XML messages that "double-free" memory. Executing the command to free a specific memory address more than once can cause memory leakage that allows the attacker to write commands or other data into memory. This can cause the system to execute commands or it could crash the system. Vulnerable devices run the Cisco ASA software with WebVPN enabled. Cisco has issued a patch, but to get it, customers without current maintenance contracts have to contact Cisco's Technical Assistance Center and ask nicely. A few days after news of this bug became public, Cisco said it was worse than initially thought. On their own, they identified additional attack vectors and features that are affected by the bug. Worse still, Cisco found that the original fix was incomplete and they issued a patched patch.

Asus router flaw has been fixed

FortiGuard Labs Discovers Vulnerability in Asus Router
by David Maciejak of Fortinet's FortiGuard Labs   January 30, 2018
Bug fixes have been released for the ASUS RT-N18U, RT-AC66U, RT-AC68U, RT-AC86U, RT-AC87U, RT-AC88U, RT-AC1900, RT-AC2900, RT-AC3100, RT-AC3200 and RT-AC5300. The flaw seems fairly minor. An attacker can forge an HTTP request that injects operating system commands that get executed as root. The flaw is due to unsanitized parameters passed to the apply.cgi script. It is mostly a LAN side attack, unless remote administration is enabled via HTTP. Asus fixed this quickly. It was reported to them Dec 23, 2017 and 4 days later they gave FortiGuard a patch to verify. The fix started rolling out Jan. 2, 2018.

Two Asus router flaws have been fixed

Advisory - Asus Unauthenticated LAN Remote Command Execution
by SecuriTeam a division of Beyond Security   January 22, 2018
Two vulnerabilities in AsusWRT (the firmware on Asus routers) version can lead to remote command execution from the LAN side. Independent security researcher, Pedro Ribeiro discovered the flaws. Asus has released patches as of version One flaw is that the handle_request() routine allows an unauthenticated user to perform a POST request for certain actions. An attacker can trigger the vulnerabilities and reset the admin password. This, in turn, lets an attacker login to the web interface, enable SSH, reboot the router and login via SSH. Another flaw is in the same code that was reported buggy in 2015, the infosvr service which listens on LAN side UDP port 9999. The buggy routers are the RT-AC88U, RT-AC3100, RT-AC86U, RT-AC68U and RT-AC66U.
Update March 16, 2018: One of these bugs makes routers that are enabled for Remote Administration via HTTP (as opposed to HTTPS) vulnerable to attack. This may explain the multiple reports of DNS hijacking on Asus routers, described above in March 2018.

Flaws in D-Link routers in Israel

Advisory - D-Link DSL-6850U Multiple Vulnerabilities
by SecuriTeam a division of Beyond Security   January 1, 2018
An independent security researcher reported two flaws in the D-Link DSL-6850U versions BZ_1.00.01 - BZ_1.00.09. The router is manufactured by D-Link for Bezeq in Israel. Bezeq was informed of the vulnerability on June 9, and released patches to address the vulnerabilities. One flaw was a default account that could not be disabled. The userid and password were both "support". In addition, remote administration was enabled by default and a flaw allowed for Remote Command Execution.

To keep this page small, router bugs from earlier years have been omitted by default. To see them, click the buttons below.


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