regreSSHion: RCE in OpenSSH's server, on glibc-based Linux systems (CVE-2024-6387)

The following summary from Debian's security list:

The Qualys Threat Research Unit (TRU) discovered that OpenSSH, an implementation of the SSH protocol suite, is prone to a signal handler race condition. If a client does not authenticate within LoginGraceTime seconds (120 by default), then sshd's SIGALRM handler is called asynchronously and calls various functions that are not async-signal-safe. A remote unauthenticated attacker can take advantage of this flaw to execute arbitrary code with root privileges. This flaw affects sshd in its default configuration.