Update: Cisco investigates reported Linksys router flaw

Cisco is investigating a reported vulnerability in Linksys firmware that would allow a hacker to gain full control of the wireless router.

Security vendor DefenseCode discovered the flaw and reported it to Cisco “months ago.” Because Cisco has yet to commit to a fix, DefenseCode plans to release details in a couple of weeks.

Cisco confirmed Tuesday that it had spoken to DefenseCode, but had yet to determine whether the vulnerability exists.

“We do not have enough information to confirm a new vulnerability,” a Cisco spokesman said in an email. “We’re continuing our own internal assessment.”

DefenseCode said the flaw is in the default installation of Linksys routers, which are primarily used in home networks. The company posted a YouTube video showing a proof-of-concept exploit being used to gain root access to a Linksys model WRT54GL router.

[See also: Researcher at RSA: Web page can take over your router]

The device was running the latest version of firmware, 4.30.14, but DefenseCode said the vulnerability is in all previous versions as well. “Exploit shown in this video has been tested on Cisco Linksys WRT54GL, but other Linksys versions/models are probably also affected,” the company said in its blog post.

Third parties interested in buying the exploit have approached DefenseCode. “We already got a few shady inquiries about buying the exploit,” Leon Juranic, chief executive of DefenseCode, said on Wednesday in an email. “However, we declined them. We don’t sell exploits.”

In December, Cisco hired Barclays to find a buyer for Linksys, Bloomberg reported. The network equipment maker was looking to sell the unit as part of its strategy to get rid of its consumer businesses in order to focus on corporate products.

Also last year, Cisco had to deal with a firestorm of complaints from customers angry over the company’s decision to have Linksys customers use an Internet-based administration service as the default tool for managing their routers.

Cisco later retreated and brought back as the default the traditional setup and management over the local network. Customers would have to opt-in to the cloud service, which raised concerns about privacy and having to accept automatic firmware updates.

Report updated on 1/16/13 with comments from DefenseCode.