HTB22903: XSS in Spitfire CMS

[advisory () htbridge ch]

Vulnerability ID: HTB22903
Reference: http://www.htbridge.ch/advisory/xss_in_spitfire_cms.html
Product: Spitfire CMS
Vendor: Spitfire ( http://spitfire.clausmuus.de/ ) 
Vulnerable Version: 1.0.436 
Vendor Notification: 15 March 2011 
Vulnerability Type: XSS
Risk level: Medium 
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/) 

Vulnerability Details:
The vulnerability exists due to failure in the "index.php" script to properly sanitize user-supplied input in 
"cms_username" variable from cookies.
User can execute arbitrary JavaScript code within the vulnerable application.
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.

The following PoC is available:

[code]
GET / HTTP/1.1
Cookie: cms_username=admin"><script>alert("XSS")%3b</script>
[/code]