XSS vulnerability in Gekko Web Builder

[advisory () htbridge ch]

Vulnerability ID: HTB22474
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_gekko_web_builder.html
Product: Gekko Web Builder
Vendor: Baby Gekko IT Consulting ( http://www.babygekko.com/ ) 
Vulnerable Version: v0.90 ALPHA 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 "/admin/index.php" script to properly sanitize user-supplied input in 
"app" 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/admin/index.php?app=settings";><script>alert(document.cookie)</script>