source: https://www.securityfocus.com/bid/37351/info

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

An attacker may leverage this issue 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 cookie-based authentication credentials and launch other attacks.

This issue affects versions prior to Horde 3.3.6.

Note that additional products that use the Horde framework may also be vulnerable.

http://www.example.com/horde-3.3.5/admin/phpshell.php/%22%3E%3Cscript%3Ealert%288%29;%3C/script%3E%3Cform%20/?Horde=<sessid>