XSS vulnerability in CompuCMS

[advisory@xxxxxxxxxxx]

Vulnerability ID: HTB22584
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_compucms.html
Product: CompuCMS  
Vendor: CompuSoft A/S ( http://www.compusoft.dk/ ) 
Vulnerable Version: Current at 06.08.2010 and Probably Prior Versions
Vendor Notification: 09 August 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 
"_CompuCMS/_CMS_output/_visbillede.asp" script to properly sanitize 
user-supplied input in multiple variables. 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/_CompuCMS/_CMS_output/_visbillede.asp?billede=1.jpg&tekst=%3Cscript%3Ealert%28document.cookie%29%3C/script%3E

http://host/_CompuCMS/_CMS_output/_visbillede.asp?billede=1.jpg%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&tekst=