source: http://www.securityfocus.com/bid/25448/info

AutoIndex PHP Script is prone a cross-site scripting vulnerability because it fails to sufficiently sanitize user-supplied input 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.

AutoIndex PHP Script 2.2.1 is vulnerable; other versions may also be affected. 

http://www.example.com/AutoIndex/index.php?search=asdf&search_mode=[xss]