source: https://www.securityfocus.com/bid/13089/info

ModernBill is affected by a cross-site scripting vulnerability.

This issue is due to a failure in the application to properly sanitize user-supplied input to the 'aid' parameter. This may facilitate the theft of cookie-based authentication credentials as well as other attacks.

ModernBill 4.3 and prior versions are vulnerable to this issue.

http://www.example.com/order/orderwiz.php?v=1&aid=[XSS]