NetDSL ADSL Modem 800 with Microsoft Network firmware 5.5.11 allows remote attackers to gain access to configuration menus by sniffing undocumented usernames and passwords from network traffic.
http://www.securityfocus.com/bid/6064
http://www.iss.net/security_center/static/10498.php
http://cert.uni-stuttgart.de/archive/bugtraq/2002/10/msg00416.html