Nortel CVX 1800 is installed with a default "public" community string, which allows remote attackers to read usernames and passwords and modify the CVX configuration.
http://www.kb.cert.org/vuls/id/403315
http://www.iss.net/security_center/static/8848.php
http://online.securityfocus.com/archive/1/267627
http://archives.neohapsis.com/archives/bugtraq/2002-04/0272.html