* This account is only available to connect in the loopback interface, so a
* local user will be able to connect to Serv-u with this account and create
* an ftp user with execute rights. after the user is created, just connect
* to the ftp server and execute a raw "SITE EXEC" command. the program will
* be execute with SYSTEM privileges.
http://www.k-otik.com/exploits/08082004.ServuLocal.c.php




