source: http://www.securityfocus.com/bid/21428/info
 
Vt-Forum Lite is prone to multiple cross-site scripting vulnerabilities because it fails to properly sanitize user-supplied input. 
 
An attacker may leverage these issues to have arbitrary script code execute in the browser of an unsuspecting user in the context of the affected site. This may help the attacker steal cookie-based authentication credentials and launch other attacks.
 
The attacker may also be able to conduct HTML-injection attacks through unspecified fields on the 'vf_newtopic.asp' script page.
 
These issues affect version 1.3; other versions may also be vulnerable.

http://www.example.com/[scriptpath]/vf_newtopic.asp<iframe height=500 src="http://www.example2.com/yoursite.html">