Regression in signal handler.

This vulnerability is exploitable remotely on glibc-based Linux systems, where syslog() itself calls async-signal-unsafe functions (for example, malloc() and free()): an unauthenticated remote code execution as root, because it affects sshd’s privileged code, which is not sandboxed and runs with full privileges.

  • refaloEnglish
    23·
    6 months ago

    what does that mean? I don’t understand multiple signs in the same sentence and what is the significance of having “OpenSSH” in the middle?

    • cucumberbobEnglish
      41·
      6 months ago

      You can read them as separate statements with the middle repeated and a logical AND between them:

      If (8.5p1 <= your OpenSSH version) AND (your OpenSSH version < 9.8p1) Then you are vulnerable

      It’s the same as saying if your OpenSSH version is between these two versions (including 8.5p1, but not 9.8p1), then you are vulnerable

      • refaloEnglish
        23·
        6 months ago

        I don’t get it… wouldn’t everything < 9.8p1 already include <= 8.5p1? So why is it even necessary to mention?

        • rushactionEnglish
          4·
          6 months ago

          Because this is a regression and this particular issue was introduced in 8.5p1. So it only affects versions newer than that, up until when it was fixed in 9.8p1.

        • towerfulEnglish
          2·
          6 months ago

          For an integer, 4 < x < 6 x has to be 5. It’s the only value that satisfies all sides of the equation.
          You are deriving a set of values for open ssh that satisfies all sides of the equation.

          I think it’s more of a mathematical representation than programming representation (I mean, I don’t know of a language that would accept that syntax).
          Certainly psuedocode would have quick statements like this

          • refaloEnglish
            2·
            6 months ago

            seems to work fine in C and I can find quite a bit of examples of it being used actually