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tehjh's profile
Jann Horn
Jann Horn
Jann Horn
@tehjh

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Jann Horn

@tehjh

works at Google Project Zero. personal account.

Joined August 2011

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    1. Tavis Ormandy‏Verified account @taviso 20 Nov 2018
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      I hate the phrase "raising the bar", I've noticed people use it when they're pitching some low-quality mitigation that makes the attacker do some busy work but doesn't fundamentally prevent them from achieving their original goal. 😈

      32 replies 30 retweets 246 likes
      Show this thread
    2. Mohammed Aldoub‏ @Voulnet 20 Nov 2018
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      Replying to @taviso

      Where do you set the line between effective mitigations that make defense in depth better vs low quality mitigations that are simply another cute challenge to an attacker?

      1 reply 0 retweets 2 likes
    3. Tavis Ormandy‏Verified account @taviso 20 Nov 2018
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      Replying to @Voulnet

      If it requires a new capability the attacker hasn't already demonstrated (another bug class, for example), great. If it requires some busy work or jumping through a few hoops, then you've just added significant complexity for questionable gains.

      2 replies 4 retweets 22 likes
    4. Fourteen macaws in a trenchcoat‏ @0xMatt 20 Nov 2018
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      Replying to @taviso @Voulnet

      In some circumstances though, the difference between making something a targeted attack vs something easy to write as a worm is still meaningful - in that it takes worms and automation out of the list of stuff blue teams have to deal with while working on better defenses overall.

      1 reply 0 retweets 9 likes
    5. Fourteen macaws in a trenchcoat‏ @0xMatt 20 Nov 2018
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      Replying to @0xMatt @taviso @Voulnet

      If a small amount of effort "raises the bar" enough to free up a large amount of employee hours to KEEP raising the bar further and further, I can't completely see that as wasted effort.

      2 replies 0 retweets 9 likes
    6. Eduardo Vela‏ @sirdarckcat 22 Nov 2018
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      Replying to @0xMatt @taviso @Voulnet

      What if the mitigation also introduces problems? Such as confusion, complexity, or even it's own vulnerabilities.

      2 replies 0 retweets 2 likes
    7. Fourteen macaws in a trenchcoat‏ @0xMatt 22 Nov 2018
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      Replying to @sirdarckcat @taviso @Voulnet

      Then that's bad.

      1 reply 0 retweets 2 likes
    8. Fourteen macaws in a trenchcoat‏ @0xMatt 22 Nov 2018
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      Replying to @0xMatt @sirdarckcat and

      A good example of this in practice is chroot. In .gov I used to chroot a lot of servers. chroot is pure bar-raising mitigation and fixes nothing. "Real" security people would say it's not a legitimate protection because there are ways to break out of the root. BUT:

      2 replies 0 retweets 0 likes
      Jann Horn‏ @tehjh 22 Nov 2018
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      Replying to @0xMatt @sirdarckcat and

      (fwiw, linux nowadays has mount namespaces, which do come with some security guarantees)

      8:07 AM - 22 Nov 2018
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      • Fourteen macaws in a trenchcoat
      1 reply 0 retweets 1 like
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        2. Fourteen macaws in a trenchcoat‏ @0xMatt 22 Nov 2018
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          Replying to @tehjh @sirdarckcat and

          Yeah, this was Solaris in 2002 - 2012 ;) It's a technique past its prime which is why I don't use it anymore but I still think it is a good example of the general argument.

          1 reply 0 retweets 0 likes
        3. Fourteen macaws in a trenchcoat‏ @0xMatt 22 Nov 2018
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          Replying to @0xMatt @tehjh and

          And that's actually where I think a lot of times offensive and defensive people are talking past each other on this issue. Defense is not trying to just raise the bar against AN attacker, they're trying to raise it against ALL POSSIBLE attackers.

          1 reply 0 retweets 0 likes
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