XSS vulnerability in i-Web Suite

Vulnerability ID: HTB22544
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_i_web_suite.html
Product: i-Web Suite
Vendor: immediaC world wide Inc ( http://www.immediac.com/ )
Vulnerable Version: Current at 27.07.2010 and Probably Prior Versions
Vendor Notification: 27 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 "default.asp" script to properly sanitize user-supplied input in "errmsg" 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/default.asp?mn=1.2.444&errmsg=%3Cscript%3Ealert%28document.cookie%29%3C/script%3E