Zbtlink Electronics (Zbtlink), a Chinese router maker, halted sales of its routers after a remote-accessible "backdoor" was found and began security updates. As security concerns mount over Chinese-made networking gear, warnings are also growing about vulnerabilities to external attacks (hacking) surrounding the issue.
On the 6th (local time), Zbtlink said in a statement on its website that it had halted sales of routers in which a backdoor was found and removed the problematic software. It added that it is developing an update to fix the security issue.
Earlier, cybersecurity firm VulnCheck said it had found a backdoor called "Endlessdoors" in more than 20 router models made by Zbtlink, which is headquartered in Shenzhen, China. Jacob Baines, VulnCheck's chief technology officer, who led the research, said the backdoor could serve as a pathway not only to the router but also to access or control other devices on the same network.
According to Baines, the backdoor was designed to automatically connect every 35 seconds to a specific IP address and a domain registered in China. If the domain is managed or seized by a third party, it means they could take over the router and then access other devices on the same network. "Routers installed worldwide remain vulnerable to malicious takeover through the backdoor," Baines said, adding, "The only response users can take is to remove the router from the network and check for compromise."
Reuters, citing VulnCheck's report, said the backdoor was found in more than 20 router models sold under the Zbtlink and Wiflyer brands. The number of installed units worldwide is estimated at no fewer than 100,000. The exact locations of installation and the number of devices currently in use were not confirmed.
Zbtlink said the function was a tool for technical support. It said it was merely a technology prepared to remotely assist with device checks and settings only when a customer clearly requested and approved it. Zbtlink also claimed it had never used the technology for unauthorized access. However, Baines countered that Zbtlink's explanation does not account for why the feature's name was made hard to identify and why it was implemented in a way that allows remote manipulation or takeover from outside.
The backdoor controversy is expected to continue for the time being, as it comes amid growing security concerns in Western countries over Chinese-made networking equipment. Earlier this year, the United States moved to restrict imports of foreign-made routers for national security reasons, exempting some non-Chinese companies from the measure. The Canadian government also issued a security advisory related to the controversy.