source: https://www.securityfocus.com/bid/22984/info

Horde Framework is prone to a cross-site scripting vulnerability because the application fails to properly sanitize user-supplied input.

Attacker-supplied HTML and script code would execute in the context of the affected site, potentially allowing the attacker to steal cookie-based authentication credentials.

This issue affects versions prior to 3.1.4. 

http://www.example.com/horde/[Horde_App]/login.php?new_lang=[xss]