The SSL Sky is Falling?

With headlines like “New cyber threat compromises financial information – Experts say new threat could affect millions of sites”, you would think that the trust model of the internet is finally crumbled.

Following an hour long Friday evening wait for the demo, the Ekoparty demo for the SSL hack was staged. And it was interesting that the attack succeeded in cracking the SSL confidentiality model as implemented by the Mozilla Firefox browser when communicating with paypal.com web servers over https. At the same time, it seemed to be an impractical exploit targeting a weakness that was fixed three months ago in Chromium source code.

Also of note, is the fact that the attack has been well known for almost 10 years, it’s just that there hasn’t been a practical exploit implementing the attack. And that they refined their blockwise attack model far better than previous chosen-plaintext attack models, making it more effective than prior attacks.

So there seems to be another good security reason to use Google’s Chrome browser, for those of you highly sensitive to security issues. Also interesting were some of the tricks they used to make it work. While they couldn’t get it to work in pure javascript or flash, they implemented the exploit in a Java applet and attacked the stream between Firefox and https://paypal.com. The “tricks” they used to bypass “Same Origin Policy” with Java were surprising, and they came up with the entire stolen session cookie with which to log in to paypal.com as the victim over http in under three minutes. While I am sure that the other browser vendors will update their CBC encryption routines to better randomize their IV and overcome this attack as suggested almost ten years ago, one could use Chrome and maintain secure communications in regards to this exploit. To me, this exploit is a low risk one because of its impracticality. Whether they properly disclosed their work to all browser vendors, giving developers plenty of time prior to disclosure remains a question to me, but they did contact at least the Chrome team. Interesting research and impressive effort implementing a difficult to work concept certainly. These guys know crypto and communications technologies. But the sky has not fallen. Yet.

For related technical information, and thoughts from relevant developers and researchers, please check out my “Related Links” list to the right side of the post text. I try to be thorough in my selection.

UPDATE(9/26): Microsoft advises that they are investigating the matter for their Internet Explorer browser customers, stating that the issue is low risk anyways, “Considering the attack scenario, this vulnerability is not considered high risk to customers”. Perhaps they were one of the browser vendors that were not contacted about the vulnerability.