source: https://www.securityfocus.com/bid/26566/info

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

Exploiting this issue allows attackers to execute arbitrary HTML or script code in a user's browser session in the context of an affected site. This may allow the attacker to steal cookie-based authentication credentials and launch other attacks.

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

http://www.example.com/vBTube.php?do=search&search=<script>alert(document.cookie)</script>