XSS vulnerability in Spitfire

Vulnerability ID: HTB22482
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_spitfire.html
Product: Spitfire
Vendor: Claus Muus ( http://spitfire.clausmuus.de/ )
Vulnerable Version: 1.0.336 and Probably Prior Versions
Vendor Notification: 08 July 2010
Vulnerability Type: 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 "/site/cont_index.php" script to properly sanitize user-supplied input in "cms_id" 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:
http://host/site/cont_index.php?cms_id=PAGE_ID"><script>alert(document.cookie)</script>