If you're surfing the web from a wireless router supplied by some of the biggest device makers, there's a chance Samy Kamkar can identify your geographic location.
That's because WiFi access points made by Westell and others are vulnerable to XSS, or cross-site scripting, attacks that can siphon a device's media access control address with one wayward click of the mouse. Once in possession of the unique identifier, Kamkar can plug it in to Google's Google Location Services and determine where you are.
"It's actually scary how accurate it is," said Kamkar, the author of the Samy Worm, a self-replicating XSS exploit that in 2005 added more than 1 million friends to his MySpace account and in the process knocked the site out of commission. "I've found that with a single MAC address, I've always been spot on with the tests I've done."
Kamkar, who tweeted about the vulnerability Tuesday, has posted a proof-of-concept attack here. For now, it works only on FiOS routers supplied by Verizon, and then only when users are logged in to the device's administrative panel. With a little more work, he said he can make it exploit similar XSS holes in routers made by other manufacturers.
With one very important difference, Kamkar's proof-of-concept is similar to a Firefox feature that allows users to get customized content by automatically sharing their location with websites they're visiting. Whereas the open-source browser is careful to ask permission before broadcasting geographic information, Kamkar's attack could happen completely unbeknownst to the user.
It complements a separate attack Kamkar devised for remotely accessing Westell UltraLine Series3 routers that Verizon provides to its FiOS customers. It gives the hacker administrative control over the devices of customers who click on the link while logged in to the administrative panel.
"We essentially piggyback off of the logged in user's cookies," Kamkar told The Register. An attacker could then force the router to use a DNS server that sends users to malicious sites, open vulnerable ports or make other changes that leave the user open to attack.
Verizon spokesman Jim Smith downplayed the significance of the attacks on the Westell routers.
"Our customers are advised to follow good practices and log out of any link or operation that is password protected whenever they are done using it," he wrote in an email. "Accounting for that is not a technology issue but a best practices issue that resides with the customer."
Kamkar is the co-founder of a VoIP company located in Los Angeles who does security research in his spare time. His findings add to growing awareness that routers made by a variety of providers - including Thomson, Netgear, Linksys and even open-source developers are susceptible to remote attacks. More often than not, the vulnerabilities lie in poorly written web interfaces, that can also put users of webcams, printers, VoIP phones and picture frames at risk. ®