Zbtlink Routers Chinese manufacturer suspends sales after security backdoor discovery

Zbtlink Routers have come under scrutiny after Chinese networking equipment maker Zbtlink Electronics suspended sales of several router models linked to a hidden security backdoor. The company also removed the affected firmware from its website. It is now preparing software updates to fix the vulnerability.

Women’s Asia Cup ACC announces full schedule for Women’s T20 Asia Cup 2026

The action followed findings by cybersecurity company VulnCheck. Researchers identified the hidden feature in at least 20 router models manufactured by the Shenzhen-based firm. They warned that attackers could exploit the flaw to gain control of affected routers. They also cautioned that hackers could access other devices connected to the same network.

Company defends hidden feature

Zbtlink acknowledged the discovery. However, the company said the feature, called “Endlessdoors,” served only as an after-sales technical support tool. It explained that technicians used it only with customers’ permission to troubleshoot and configure devices.

Furthermore, the company stressed that it had never used the feature for unauthorised access.

Experts question the explanation

However, VulnCheck remained unconvinced. Chief Technology Officer Jacob Baines said the hidden tool contacted a specific IP address and a Chinese-registered domain every 35 seconds.

According to Baines, anyone who gained control of those domains could hijack vulnerable routers. As a result, attackers could compromise other devices on the same network.

Moreover, he advised users to disconnect affected routers until Zbtlink releases security updates. He also urged customers to monitor their networks for suspicious activity.

Cybersecurity concerns continue

Meanwhile, the discovery has renewed concerns about the security of Chinese-made networking equipment. Canada also issued a security advisory this week after the vulnerability came to light.

Finally, Baines questioned why the hidden feature remained difficult to detect. He added that Zbtlink had not explained why it implemented the tool in a way that attackers could exploit.