source: https://www.securityfocus.com/bid/19948/info

XHP CMS is prone to a cross-site scripting vulnerability because it fails to sufficiently sanitize user-supplied data.

Exploiting this issue could allow an attacker to steal cookie-based authentication credentials and to launch other attacks.

Version 0.5.1 is vulnerable; other versions may also be affected.

http://www.example.com/index.php?errcode=<script>alert(document.cookie);</script>