source: https://www.securityfocus.com/bid/8074/info

It has been reported that the K2 Toolkit does not sufficiently sanitize input by users. Because of this, it may be possible for an attacker to launch an attack that results in the execution of hostile HTML or script code in the browsers of users that have loaded a malicious link created by the attacker.

http://www.example.com/[search].jsp?[query]=><img src=javascript:alert(document.cookie)>