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.

  • cucumberbobEnglish
    41·
    5 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·
      5 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·
        5 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·
        5 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·
          5 months ago

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