A major flaw has been found that enables a man-in-the-middle attacks against SSL connections. Several other media outlets are reporting, but Kelly Jackson Higgins has a nice summary over at Dark Reading, and betanews has a much more detailed discussion. According to Marsh Ray at PhoneFactor:

“The bug results in a set of related attacks that allow a man-in-the-middle to do bad things to your SSL/TLS connection. The (attacker) in the middle is able to inject his own chosen text into what your application believes is an encrypted, secure communications channel,” says Ray, a senior software development engineer for PhoneFactor. “This has implications for all protocols that run on top of SSL/TLS, such as HTTPS … What’s different with this (bug) is that both the client and server need to be patched to restore the full security guarantees that are expected with TLS.”

The communication process two parties go through to establish a trusted connection inadvertently leaves some response information in clear text during part of the dialogue. Basically when they agree to change some of the session attributes the protocol leaves some information exposed:

“Methods exist for one or the other party to request a change in the parameters of their transactions, perhaps to switch to a different, stronger cipher suite … In a situation similar to someone’s e-mail application replying to your e-mail with a message whose subject line begins, RE:, the conversation between client and server over what to change to, contains a reference to the request for renegotiation – the request that had, when sent earlier, been encrypted. Now it’s not, and that’s the problem. “

The fix for this should be relatively straightforward and, from what I understand, should be available within the next few days. The issue becomes deploying a patch to a piece of code used for just about any secure communication session. So plan on patching a lot of applications in the coming weeks!

PhoneFactor named their efforts ‘Project Mogul’, which has nothing to do with The Mogull so far as I know.