This backdoor is a software backdoor - there may be hardware backdoors too. Hardware backdoors are much, much harder to find as there is no real way to track on

This backdoor is a software backdoor - there may be hardware backdoors too. Hardware backdoors are much, much harder to find as there is no real way to track one down without trying to reverse the actual hardware itself, and that is close to impossible. So while we can confirm there is a software backdoor in this router, we can't confirm if any other router does or doesn't have a hardware one.