It baffles me that any router manufacturer would have the nerve to hard-code login credentials into their routers.
I'm not advocating this practice at all, but consider that BIOS passwords could be easily bypassed with a hardcoded "default password". The one I still remember is "lkwpeter" and if you Google that one you'll find plenty more. That practice slowly faded away but many laptops' BIOS passwords are still overridable with a "manufacturer access" password that is derived from the serial number/asset tag.
The history of backdoors in hardware is a long one, so I'm not surprised to see them show up in routers. D-link had one a while back, and there have been several more discovered since then.
As you say, perhaps what keeps them from being exploited more is that they are not accessible from the Internet-facing side.
True, hardware backdoors have been around forever. The difference here is a BIOS backdoor password has a somewhat legitimate reason. You can't just hit a reset button on your PC if you forget the BIOS credentials the way you can on your router.
Also, a router being programmed like this exposes every device routed through it, whereas a BIOS backdoor only gives you access to the single device to which you have physical access. My surprise comes from the gall of the manufacturers as they should be fully aware of these implications.
It's often done to make support calls easier. You could spend a long time trying to explain to a frustrated customer how to use telnet (Type a slash... no, that's backslash. No don't type the word "slash"...) Or you could just say "let me log onto the router and fix it for you."
Telnet wouldn't help if they forgot the password and it wasn't hard-coded as a back door. Also, the support tech wouldn't be able to access it remotely unless some of the things I mentioned in the original comment were true.
Wouldn't it be easier to just say, "hold down the reset button on the back for 30 seconds"?
I'm not advocating this practice at all, but consider that BIOS passwords could be easily bypassed with a hardcoded "default password". The one I still remember is "lkwpeter" and if you Google that one you'll find plenty more. That practice slowly faded away but many laptops' BIOS passwords are still overridable with a "manufacturer access" password that is derived from the serial number/asset tag.
The history of backdoors in hardware is a long one, so I'm not surprised to see them show up in routers. D-link had one a while back, and there have been several more discovered since then.
As you say, perhaps what keeps them from being exploited more is that they are not accessible from the Internet-facing side.