Chinese-Made Zbtlink Routers Ship With Backdoor That Opens Unauthenticated Root Shells

Cybersecurity researchers have found a backdoor in routers made by Zbtlink, a Chinese company. The backdoor is present in at least 20 router models and is included in the firmware, which suggests it was intentionally added by the manufacturer. All 21 available firmware images from Zbtlink, spanning over two years, contain the backdoor. The backdoor starts automatically and tries to connect to servers in China. This vulnerability allows unauthenticated root shells to be opened, potentially giving attackers full access to the affected devices. The backdoor's presence in devices shipped from the factory raises concerns about the security of these routers.