'Bar Mitzvah Attack' Plagues SSL/TLS Encryption

ancientribe writes Once again, SSL/TLS encryption is getting dogged by outdated and weak options that make it less secure. This time, it's the weak keys in the older RC4 crypto algorithm, which can be abused such that an attacker can sniff credentials or other data in an SSL session, according to a researcher who revealed the hack today at Black Hat Asia in Singapore. A slice: Bar Mitzvah exploits the weak keys used by RC4 and allows an attacker to recover plain text from the encrypted information, potentially exposing account credentials, credit card data, or other sensitive information. And unlike previous SSL hacks, this one doesn't require an active man-in-the-middle session, just passive sniffing or eavesdropping on SSL/TLS-encrypted connections, [researcher Itsik] Mantin says. But MITM could be used as well, though, for hijacking a session, he says.

Comments

Re:Duh

[thegarbz]

The flaws in RC4 have been known about for a long time but were thought irrelevant in the scheme of SSL/TLS to the point where RC4 was the preferred cipher suit only a few years ago as it was one of the few that were able to mitigate the BEAST attack. So the GP's comment that there's no surprise since RC4 has been known to be weak for a decade isn't quite the full story.

It was only in 2013 where RC4 became strictly taboo for use in SSL/TLS with the exposure of new exploitable vulnerabilities on top of the several previous weaknesses identified, and last month RFC7465 effectively banned the cipher's use in TLS.