'Surf Jacking' Threatens Secure Browser Sessions

Researchers at Enable Security this week published a proof of concept that shows how an attacker might hijack browser sessions secured by the popular HTTPS encryption scheme.

HTTPS is used by many banks, e-commerce sites, and other businesses to provide a secure link between a browser and a Web server. But in a paper published Sunday, Enable Security's Sandro Gauci outlined a way that hackers might hijack HTTPS links and defeat the encryption.

In a nutshell, the proof of concept describes a way to use the "301 Moved Permanently" redirection message to fool browsers that are seeking HTTPS sessions. Rather than breaking the encryption, surf jacking essentially takes advantage of the fact that many HTTPS servers and browsers do not make use of the "secure" flag in the browser cookie.

"The result is that, even though the traffic between the server and client is transported over a secure protocol, an attacker sitting in between the victim client and the victim Web server can launch a downgrade attack to reveal the session cookie," Gauci states in the paper. A short video of the exploit is also available on the Web.

The new proof of concept builds on Errata Security's concept of "side jacking" HTTP sessions, which was demonstrated at the Black Hat conference last year. (See 'Sidejacking' Tool Unleashed.)

— Tim Wilson, Site Editor, Dark Reading