Vulnerability found:
19 June 2007

Severity level:

Adrian Pastor and Jan Fry of ProCheckUp Ltd ( With thanks to Petko D. Petkov for suggesting the eval(name) technique.

F5 Networks FirePass 4100 SSL VPN is vulnerable to XSS within the "my.activation.php3" server-side script.
No authentication is required to exploit this vulnerability.


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.

CVE reference


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

Proof of concept:
The payload in the example is
which injects a 'textarea' box
The following PoC HTML page would run JavaScript without any restrictions from a third-party file ('' in this case):

%29%3C/script%3E%3C%21-- " width ="0%" height="0%" name="xss=document.body.appendChild

Successfully tested on:
Server environment:
F5 FirePass 4100
Client environment:
Microsoft Internet Explorer 7.0.5730.11

How to fix:
F5 Networks has issued SOL7923:

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