source: https://www.securityfocus.com/bid/51966/info

CubeCart is prone to a URI-redirection vulnerabilities because the application fails to properly sanitize user-supplied input.

A successful exploit may aid in phishing attacks; other attacks are possible.

CubeCart 3.0.20 is vulnerable; other versions may also be affected. 

http://www.example.com/cube/index.php?act=login&redir=Ly95ZWhnLm5ldC8%3D
http://www.example.com/cube/cart.php?act=reg&redir=L2N1YmUvaW5kZXgucGhwP2FjdD1sb2dpbg%3D%3D