CVE-2024-7589

A signal handler in sshd(8) may call a logging function that is not
async-signal-safe. The signal handler is invoked when a client does not
authenticate within the LoginGraceTime seconds (120 by default). This
signal handler executes in the context of the sshd(8)'s privileged code,
which is not sandboxed and runs with full root privileges.
This issue is another instance of the problem in CVE-2024-6387 addressed by
FreeBSD-SA-24:04.openssh. The faulty code in this case is from the
integration of blacklistd in OpenSSH in FreeBSD.
As a result of calling functions that are not async-signal-safe in the
privileged sshd(8) context, a race condition exists that a determined
attacker may be able to exploit to allow an unauthenticated remote code
execution as root.

Notes