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Researchers Devise New Attack Techniques Against SSL 33

Posted by samzenpus
from the protect-ya-neck dept.
alphadogg writes "The developers of many SSL libraries are releasing patches for a vulnerability that could potentially be exploited to recover plaintext information, such as browser authentication cookies, from encrypted communications.The patching effort follows the discovery of new ways to attack SSL, TLS and DTLS implementations that use cipher-block-chaining (CBC) mode encryption. The new attack methods were developed by researchers at the University of London's Royal Holloway College. The men published a research paper and a website on Monday with detailed information about their new attacks, which they have dubbed the Lucky Thirteen. They've worked with several TLS library vendors, as well as the TLS Working Group of the IETF, to fix the issue."
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Researchers Devise New Attack Techniques Against SSL

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  • by GameboyRMH (1153867) <gameboyrmh@gm[ ].com ['ail' in gap]> on Wednesday February 06, 2013 @10:06PM (#42816415) Journal

    Rumors have been going around for a while that the NSA is able to crack certain forms of SSL or lower-level AES, and their new data center is for a "store now, decrypt later" operation. Could this be what they have?

    • Re: (Score:3, Informative)

      by Anonymous Coward

      No.

      Paranoid though I am, this is a timing attack needing multiple packets. Not something you can do 'offline'

    • by Anonymous Coward on Wednesday February 06, 2013 @10:28PM (#42816561)

      Yes, the NSA has broken AES, which is why all of the encryption standards they use for their secrets are based on it. Beccause, if they can break it, there's no way someone like, I don't know, China could.

      I consider myself on the paranoid side of tech, but even I treat rumors about the NSA seccretly breaking low level schemes the same way I treat rumors about UFOs.

      • Well it's not so far fetched as you think. They talk about it themselves:

        http://www.wired.com/threatlevel/2012/03/ff_nsadatacenter/all/ [wired.com]

        Meanwhile, over in Building 5300, the NSA succeeded in building an even faster supercomputer. “They made a big breakthrough,” says another former senior intelligence official, who helped oversee the program. The NSA’s machine was likely similar to the unclassified Jaguar, but it was much faster out of the gate, modified specifically for cryptanalysis and targeted against one or more specific algorithms, like the AES. In other words, they were moving from the research and development phase to actually attacking extremely difficult encryption systems. The code-breaking effort was up and running.

        The breakthrough was enormous, says the former official, and soon afterward the agency pulled the shade down tight on the project, even within the intelligence community and Congress. “Only the chairman and vice chairman and the two staff directors of each intelligence committee were told about it,” he says. The reason? “They were thinking that this computing breakthrough was going to give them the ability to crack current public encryption.”

        Start buying more tinfoil!

  • I'm safe (Score:5, Funny)

    by GloomE (695185) on Wednesday February 06, 2013 @10:21PM (#42816503)

    The attack relies on the slight difference in processing time of certain packets.
    My ISP is so over-subscribed that latency here varies from packet to packet by 1 second.
    They are obviously doing this on purpose to protect their clients.

  • Maybe they can break the internet (tee-hee hee). Maybe they can split it open, and make all the information inside it come tumbling, gushing out.
  • Slashdot has long had a solution for avoiding many potential SSL/TLS security-breach incidents: Deny users the privilege of utilizing SSL/TLS and that precious certificate unless there's a damn good reason, e.g., logging in. After that single use, dump 'em back to unauthenticated plaintext.

    This same tease & denial [wikipedia.org] technique is employed on all of the rest of Dice Holdings holdings—including SourceForge (albeit in a slightly more lenient manner)—logged-in users enjoy all-you-can-eat HTTPS (and

    • by ewanm89 (1052822)

      Maybe you should look up SSL stripping attacks, and then there is just sniffing the session cookies out of the air, please see firesheep for a tool designed to do this.

  • One of the attack requirements is to find the target data at a fixed offset in the SSL packets. This is the case for session cookies, which aresend back and forth in HTTP headers Set-Cookie and Cookie.

    Why don't we just randomize HTTP headers order? Such a defense, inspired by ASLR for native programs, seems cheap to implement, and would make the attacker life more difficult. There could even be padding HTTP headers inserted at random places. Something like X-Padding: foobarbuz

  • New Timing Attack (Score:5, Informative)

    by cryptizard (2629853) on Wednesday February 06, 2013 @11:24PM (#42816883) Homepage
    For lazy people a quick overview of this attack is that it uses very small differences between the amount of time it takes to decrypt a correctly padded TLS record and the time it takes to reject an incorrectly padded record (think of the padding as kind of a checksum). An attacker can modify encrypted records, send them to the server and discover whether the decryption is correctly padded or not based on the amount of time it takes to respond. With this knowledge, an attacker can interactively decrypt a record bit by bit, testing the padding over and over.

    It only works in datagram TLS (DTLS) because regular TLS terminates a session after one incorrectly padded message. It also only works over LAN where you can get really precise timing.
  • ...Firefox 18.0.3 in 3...2...1... (sigh)
  • Since the use of CBC-based cipher suites in TLS is discouraged [phonefactor.com] since BEAST attacks this is just adding more weight to the argument.
  • Once upon a time, these tax leaching researchers with Asperger's syndrome were tucked away in their dungeons. Unfortunately, someone let them out and they are now screaming loud. Don't be fooled by their screaming.

The Force is what holds everything together. It has its dark side, and it has its light side. It's sort of like cosmic duct tape.

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