Router Security Test Your Router Website by     
Michael Horowitz 
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New page on learning what your current DNS servers are: Test Your DNS Servers
 
Table of Contents
DNS Server TestsFirewall Testers
TCP Ports to TestUDP Ports to Test
TCP/IP Port Information  LAN side port testing
HNAP TestingURLs to try from your LAN
UPnP TestersModem Tests
IP Version 6 TestersAndroid apps
WebRTCAds Here

FYI: The Shodan page on this site will generate a query of your public IP address (and thus your router) on both Shodan and Censys.io.

DNS Server Tests  top

This has been moved to a new page: Test Your DNS Servers

Firewall Testers  top

Level setting: All the firewall tests below communicate with your public IP address. Usually, this is your router. There are, however, three instances where the tests are not communicating with your router. If you are connected to a VPN, the public sees the VPN server, not your router. Likewise, with Tor you end up testing the Tor exit node rather than your router. The third case involves the box your router is directly connected to. If it is just a modem, all is well. However, if it is a gateway device (combination modem, router and perhaps even a telephone adapter) from your ISP, then the device visible to the outside world may be the gateway rather than your router. For your router to be your public face on the Internet, the gateway needs to be put in Bridge mode. This dumbs it down to function only as a modem.

Port Status: An "open" port responds to unsolicited incoming requests. A "closed" port (a.k.a. "refused" in Nmap lingo) is accessible, but there is no application listening on it. A status of "stealth" (a.k.a. "filtered" to Nmap) means data sent to the port generates no response at all. This is the most secure status.

TCP Ports to Test  top

Note that while connected to a VPN, these tests test the VPN server, not your router. Same for Tor. An "open" port responds to unsolicited incoming requests. A "closed" port (a.k.a. "refused" in Nmap lingo) is accessible, but there is no application listening on it. A status of "stealth" (a.k.a. "filtered" to Nmap) means data sent to the port generates no response at all. This is the most secure status. This list is extremely incomplete.

UDP Ports to Test  top

Note that while connected to a VPN, these tests test the VPN server, not your router. Same for Tor. This list is extremely incomplete.

UDP Port testers

The links above, that test individual UDP ports, look like this
  http://www.speedguide.net/portscan.php?udp=1&port=999
This example would test port 999. SpeedGuide can also test individual ports at their Security Scan page where you can enter any port number and chose to test UDP and/or TCP.

Another website offering UDP port tests is the UDP Port Scan with Nmap page at PentTest-Tools.com. It can test a range of UDP ports, a list of UDP ports or individual ports.

LAN side port testing  top

TELNET: Individual LAN side ports can be tested from a computer on the LAN with Telnet. Windows 7 and 8.1 users will have to first install the Telnet client using: Control Panel -> Programs and Features -> click on "Turn Windows features on or off" in the left side column -> Turn on the checkbox for Telnet Client -> Click OK. On OS X ....

To use telnet on Windows, open a Command Prompt window, type "telnet ipaddress portnumber". For example: "telnet 192.168.1.1 80". There needs to be a space on both sides of the IP address. If the port is closed, Windows will complain that it "could not open connection to the host on port 80: connect failed". If the port is open, the responses vary, you may just see a blank screen. You can also telnet to a computer by name, such as "telnet somewhere.com 8080"

ID Serve: ID Serve is a small, portable, Internet Server Identification Utility for Windows, created by Steve Gibson. It was written in 2003 and has not been updated since. The initial screen explains its purpose, the Server Query tab is where it does its work. You can query a computer by name (www.amazon.com) or by IP address. It defaults to port 80, but you can force a different port by adding a colon and the port number after the computer name or IP address (no spaces). If data comes back from the query, ID Serve displays it all. This data may identify the server software. If data does not come back, the message, in my experience, will either be "The port is closed, so our connection attempt was refused" or "No response was received from the machine and port at that IP. The machine may be offline or the connection port may be stealthed". ID Serve is limited to TCP (no UDP) and does not support HTTPS.

BROWSER: You can also test a port with a web browser. For example, http://192.168.1.1:999 would test TCP port 999 (of course, modify the IP address as necessary for your router). I don't think a browser can test a UDP port, it is limited to TCP.

NMAP: This command tests UDP ports 11 through 13 on the device at IP address 1.2.3.4
  nmap -sU -p 11-13 1.2.3.4

TCP/IP Port Information  top

HNAP Testing  top

The Home Network Administration Protocol is a network device management protocol dating back to 2007. There are four problems with HNAP. One, is that it has a long history of buggy implementations. It can also tell bad guys technical details of a router making it easier for them to find an appropriate vulnerability to attack. The fact that a router supports HNAP may not be visible in its administrative interface. Worst of all, HNAP often can not be disabled. Four strikes, you're out.

You can test if a router supports HNAP by typing

  http://1.2.3.4/HNAP1/

where 1.2.3.4 is the IP address of your router. Of course, every router has two IP addresses one on the public side and one on the private side. I suggest testing for HNAP on each.

You can learn your public IP address at many websites, such as ipchicken.com and checkip.dyndns.com. For the LAN side of a router, see my Sept. 2013 blog Find the IP address of your home router.

If HNAP is enabled, this test displays basic device information about your router in an XML file. See sample output. If it fails, there will be some type of error about the web page not being able to be displayed, perhaps a 404 Not Found error.

If HNAP is enabled, try to turn it off in the router administrative interface and then test again. You may not be able to turn it off. For more, see the HNAP page.

October 26, 2018: Multiple bugs in Linksys E-Series routers were revealed by Talos in October 2018. What was not revealed was a simple way for Linksys owners to check if their routers were vulnerable. According to Jared Rittle, who found the flaws, HNAP can help. Owners can navigate to the official HNAP URL (http://1.2.3.4/HNAP1/) to see the currently installed firmware version (1.2.3.4 is the LAN side IP address of the router). This has the advantage of not needing to know the router password. For the E1200, if the firmware is at or below version 2.0.09, the router is vulnerable. For the E2500, if the firmware is at or below version 3.0.04, it is vulnerable. Owners of other E Series Linksys routers are on their own.

URLs to try from your LAN  top

In these examples, 1.2.3.4 represents the LAN side IP address of the router.

As per Scott Helme's 2014 description of his BrightBox router, try the URL below, where 1.2.3.4 is the IP address of your router. A good result returns nothing but an error message. Here is a sample of a bad result.
   http://1.2.3.4/cgi/cgi_status.js

In December 2016, Pedro Ribeiro reported on flaws in the Netgear WNR2000 router. If you own a Netgear router, it can't hurt to check for information leakage with the URL below. It may leak the device serial number.
   http://1.2.3.4/BRS_netgear_success.html

Many Netgear routers had a security flaw in December 2016 (see here and here for more). The command below tests a Netgear router. If this results in a web page with the word "Vulnerable", then the router is vulnerable. Netgear has issued fixes for all vulnerable routers.
  http://www.routerlogin.net/cgi-bin/;echo$IFS'Vulnerable'

This issue with port 32764 is explained above in the TCP Ports to Test section.
   http://1.2.3.4:32764

In September 2017, security firm Embedi found port 19541 open on many D-Link routers. It responds to commands such as one to reboot the router. They did not find any way to close the port. The default IP address is 192.168.0.1 but the router may also respond to dlinkrouter.local.
   http://1.2.3.4:19541

If there is a video surveillance system on your LAN, then hopefully it was not made by Xiongmai. In October 2018, SEC Consult published a big expose about the many ways these systems are not secure. The number of security flaws is huge. These devices are re-branded by at least 100 other companies, so to detect a Xiongmai system, they suggest viewing this page from the LAN
   http://[cameraipaddress]/err.htm
If the page exists and it refers to 'Xiongmai' at all, then read the article by SEC Consult. They also offer other suggestions for identifying Xiongmai hardware. SEC Consult feels that the security is so bad it can not be fixed and that the hardware should be discarded.

UPnP Testers  top

UPnP is dangerous because it lets computing devices (typically IoT devices) punch a hole in the routers firewall. This exposes them to the Internet where their poor security, such as default passwords, can be abused. This danger involves UPnP being enabled on the LAN side of the router. I am still looking for a LAN side tester.

UPnP on the WAN/Internet side of a router is a totally different problem. UPnP was never meant to be exposed on the Internet. The online tester below insures that your router does not respond to UPnP requests sent to it over the Internet. For more on why UPnP from the Internet side of a router is an issue at all, see my Jan. 2013 blog Check your router now, before Lex Luthor does.

UPnP is relatively hard to test for as there are two components to the protocol. Discovering UPnP enabled devices is done with the Simple Service Discovery Protocol (SSDP) which listens on UDP port 1900. The actual communication between devices is done via HTTP on varying ports. SSDP tells clients which port to use for HTTP communication. According to Rapid7, the TCP port number varies by vendor and is often chosen at random. Ugh. Their report notes that some Broadcom, D-Link and TP-Link routers use TCP port 5431, some devices use port 80 and still others use 2869.

Modem Tests  top

A modem is a computer and it too, can have bugs. Chances are the modem as an IP address such as 192.168.100.1. If nothing else, you should try to access the modem by its IP address so that technical information about your Internet connection is available to you. Also, you want to see what information is available without a password, some modems expose too much. If there is a password, then change it from the default.

As per ARRIS Cable Modem has a Backdoor in the Backdoor try to view the page below. An error viewing the page is the good result. See a video of this hack.
http://192.168.100.1/cgi-bin/tech_support_cgi

As per ARRIS DG860A NVRAM Backup Password Disclosure you should try to view the URL below. Again, an error is the good result.
http://192.168.0.1/router.data

For better security, a router may be able to block access to the modem by blocking its IP address. I blogged about modem access from the LAN side of a router in February 2015. While it can be helpful to directly access the modem, it can also be dangerous. See Talk to your modem and Using a router to block a modem. Some routers can do this, some can not. Dumbed down routers, such as the consumer mesh systems (eero, Google Wifi, Ubiquiti AmpliFi, etc) can not do this.

A great way to see if a modem is accessible from the LAN side is to ping it using the command below. Hopefully, the command fails.
ping 192.168.100.1
If it is pingable, then test Telnet access to the modem with the command below. Failure is the secure outcome.
telnet 192.168.100.1
An other good test is nmap. The simplest command is
nmap 192.168.100.1
For a much more comprehensive look at the LAN side of the modem use the below:
nmap -v -A -p 1-65535 192.168.100.1

IP Version 6 Testers  top

I know of no reason for IPv6 to be enabled on a home router. If it is enabled on yours, try to disable it then verify that it's really off. All the sites below are only available via HTTP.

Android Apps  top

WebRTC  top

Technically, WebRTC is not a router thing, it is a web browser thing. This section is here just for the heck of it. Anyone using a VPN needs to run these tests. WebRTC can expose your public IP address which is normally hidden by the VPN. If you use more than one browser, you need to run these WebRTC tests on each one.

Ads Here  top

Some routers are hacked to generate income from showing ads. This website has no ads. If you see any ads while viewing this web page, then either the router you are connected to has been hacked or your computer has.


Honorable mention goes to the Shadowserver Foundation that scans the Internet for all sorts of things that should not be there.
See The scannings will continue until the Internet improves.

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This page was last updated: November 15, 2018 10PM CT     
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