Original URL: http://www.theregister.co.uk/2012/09/07/https_sesh_hijack_attack/

SSL BEASTie boys develop follow-up 'CRIME' web attack

Ill Communication

By John Leyden

Posted in Security, 7th September 2012 12:20 GMT

The security researchers who developed the infamous BEAST attack that broke SSL/TLS encryption are cooking up a new assault on the same crucial protocols.

Online shops, banks and millions of other websites rely on SSL/TLS to encrypt sensitive information sent by punters from their web browsers. The new attack is capable of intercepting these HTTPS connections and hijacking them.

Juliano Rizzo and Thai Duong are due to present their work, dubbed CRIME, at the Ekoparty Security Conference in Argentina this month. The CRIME attack revolves around security shortcomings in TLS, but details are being withheld ahead of the presentation. The researchers warn that all versions of TLS/SSL are at risk – including TLS 1.2 which was resistant to their earlier BEAST (Browser Exploit Against SSL/TLS) technique.

The CRIME vulnerability involves exploiting cryptographic weaknesses present in the protocol. The information leaked provides enough clues to decrypt a user's supposedly protected cookies, allowing attackers to pose as their victims and hijack secure connections to websites.

"By running JavaScript code in the browser of the victim and sniffing HTTPS traffic, we can decrypt session cookies," Rizzo told Threatpost. "We don't need to use any browser plugin and we use JavaScript to make the attack faster, but in theory we could do it with static HTML."

Last year's BEAST attack was mitigated by reconfiguring web servers to use the RC4 cipher-suite rather than AES. CRIME enables miscreants to run in man-in-the-middle-style attacks and is not dependant on cipher-suites.

So far, Chrome and Firefox are confirmed to be vulnerable to CRIME, but developers at Google and Mozilla have been given a heads up on the problem and are likely to have patches available within a few weeks. Duong, who works as an information security engineer at Google, also worked with Rizzo to develop an ASP.NET "padding oracle" exploit, forcing Microsoft to rush out an emergency security patch for the popular web framework. ®