Major security warning on this one. This is why you don't source your stuff from untrusted vendors. These downstream vendors have been caught with their pants down (pun intended.... their backdoor is open) with a hidden, but not closed, back door in their security devices!
http://arstechnica.com/security/2014/04/easter-egg-dsl-router-patch-merely-hides-backdoor-instead-of-closing-it/