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submitted 4 months ago by ricdeh@lemmy.world to c/linux@lemmy.world

A signal handler race condition was found in OpenSSH's server (sshd), where a client does not authenticate within LoginGraceTime seconds (120 by default, 600 in old OpenSSH versions), then sshd's SIGALRM handler is called asynchronously. However, this signal handler calls various functions that are not async-signal-safe, for example, syslog().

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[-] catloaf@lemm.ee 2 points 4 months ago

I'm not familiar with this exploit vector. How does this bypass authentication? What's the race you're trying to win when the prompt times out?

[-] lambalicious@lemmy.sdf.org 1 points 4 months ago

And this is the reason I run infra on Debian Stable, or Oldstable, rather than eg.: Sid.

this post was submitted on 01 Jul 2024
27 points (100.0% liked)

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