source: http://www.securityfocus.com/bid/30330/info
 
XOOPS is prone to a local file-include vulnerability and a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input.
 
An attacker can exploit the local file-include vulnerability using directory-traversal strings to view local files within the context of the webserver process. Information harvested may aid in further attacks.
 
The attacker may leverage the cross-site scripting issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may let the attacker steal cookie-based authentication credentials and launch other attacks.
 
XOOPS 2.0.18.1 is vulnerable; other versions may also be affected.

http://www.example.com/scripts_path/modules/system/admin.php?fct="><script>alert("xss")</script>