source: http://www.securityfocus.com/bid/26417/info
 
X7 Chat is prone to multiple cross-site scripting vulnerabilities because the application fails to sufficiently sanitize user-supplied input.
 
An attacker may leverage these issues to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may help the attacker steal potentially sensitive information and launch other attacks.
 
These issues affect X7 Chat 2.0.4; other versions may be also vulnerable. 

http://www.example.com/upgradev1.php?INSTALL_X7CHATVERSION=<script>alert(123);</script>