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Hackers Break Browser SSL/TLS Encryption

Posted by Unknown on from the only-thoughtcriminals-use-encryption dept.

First time accepted submitter CaVp writes with an article in The Register about an exploit that appears to affect all browsers and can decrypt an active TLS session. From the article: "Researchers have discovered a serious weakness in virtually all websites protected by the secure sockets layer protocol that allows attackers to silently decrypt data that's passing between a webserver and an end-user browser." A full disclosure is scheduled for Friday September 23rd at the Ekoparty conference. Note that this only affects SSL 2.0 and TLS 1.0; unfortunately, most web servers are misconfigured to still accept SSL 2.0, and TLS 1.1 and 1.2 have seen limited deployment. The practicality of the attack remains to be determined (for one, it isn't very fast — but if the intent is just to decrypt the data for later use, that isn't an impediment).

6 of 110 comments (clear)

  1. Javascript by Hatta · · Score: 3, Informative

    From the looks of it, they use javascript on the target computer to capture some plain text which helps them break the keys. So as a temporary measure, disable javascript until browser makers catch up.

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    1. Re:Javascript by MightyMartian · · Score: 3, Informative

      Yeah, and see how many websites built in the last eight or nine years work without Javascript... Hell, for real security, go back to using Gopher!

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    2. Re:Javascript by chrb · · Score: 5, Informative

      They can. Not only is Javascript injection possible, it has already been done by at least one malicious government: "Malicious code injected into Tunisian versions of Facebook, Gmail, and Yahoo! stole login credentials of users critical of the North African nation's authoritarian government, according to security experts and news reports."

  2. Re:Should we disable TLS 1.0 in browsers? by chrb · · Score: 3, Informative

    The ramification is that you won't be able to use HTTPS on the vast majority of web sites. According to the Register, of 1 million web servers sampled: 604,242 supported TLS v1.0, 838 supported TLS v1.1, and 11 supported TLS v1.2.

  3. Re:Should we disable TLS 1.0 in browsers? by Necroman · · Score: 3, Informative

    Stolen from the thread on this on reddit:

    That's actually exactly how it's supposed to work. See Appendix E of the TLS 1.2 RFC. The client sends its highest-supported version in its first message, and the server replies with the highest-supported version that is less than or equal to the version the client sent.

    Unfortunately, some older (mostly third-party) servers break entirely if they receive something that they don't recognize. As such, TLS 1.1/1.2 is often disabled by default for compatibility reasons, even if it is supported.

    NSS (Mozilla/Firefox) and OpenSSL (used in Apache's mod_ssl) also only support up to TLS 1.0 in their stable versions, as there hasn't really been a compelling reason for them to add TLS 1.1/1.2 support until now.

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  4. SSH Tunneling by dendrope · · Score: 3, Informative

    If you have a computer at home running on a secured network, then SSH tunneling traffic while you're elsewhere should avert the problem.