Original URL: http://www.theregister.co.uk/2013/10/22/tenda_router_backdoor/

D-Link hole-prober finds 'backdoor' in Chinese wireless routers

Tenda networking kit contains easily-cracked vuln, claims researcher

By John Leyden

Posted in Security, 22nd October 2013 11:18 GMT

Security researchers say they have discovered a hidden backdoor in wireless routers from Chinese hardware manufacturer Tenda.

Craig Heffner, the same researcher who uncovered a backdoor in routers from D-link, found the latest problem. He uncovered the functionality, which ships with Tenda's products, after unpacking firmware updates and locating what he described as "suspicious code".

Attackers could take over the router and execute commands by sending a UDP packet with a special string, The Hacker News claims.

"The backdoor only listens on the LAN, thus it is not exploitable from the WAN. However, it is exploitable over the wireless network, which has WPS enabled by default with no brute force rate limiting,” Heffner explains in a detailed advisory.

“My shiny new ReaverPro box made relatively short work of cracking WPS,” he claimed, “providing access to the WLAN and a subsequent root shell on the router.”

Heffner claims the backdoor exists on Tenda’s W302R and W330R router models as as well as re-branded models, such as the Medialink MWN-WAPR150N.

"They all use the same 'w302r_mfg' magic packet string," he notes.

Follow-up work by other researchers uncovered a more comprehensive list of potentially backdoored products.

Source code for the GoAhead web server used in Tenda products has been made available on GitHub.

We've asked Tenda for its reaction but have yet to hear back from the firm. We'll update this story as and when we hear more. ®