OpenSSH: race condition in sshd allows remote code execution
OpenSSH: race condition in sshd allows remote code execution
cross-posted from: https://lemmy.pt/post/5733711
A severe vulnerability in OpenSSH, dubbed "regreSSHion" (CVE-2024-6387), has been discovered by the Qualys Threat Research Unit, potentially exposing
musl isn't vulnerable, as per https://fosstodon.org/@musl/112711796005712271
The exploit isn't that practicable, since it takes a very long time on 32 bit systems, which are ever rarer to see.
Question if I update my server and it has the new SSH (patched) package. Is that enough or do I have to restart the server as well? How can I check if the old SSH is in use currently?
For anyone in RHEL / Fedora land (or using dnf somewhere else), try
dnf needs-restartingto list executables that have mismatched files on disk vs memory. The-rflag will hint if a reboot is needed (due to things like kernel or glibc changes)The packages in most distros will also restart the server for you. Any existing SSH sessions will technically be running in vulnerable versions, but if I'm understanding the vulnerability correctly this isn't a problem, as they won't be trying to authenticate a user.
If you want to be sure, you can manually restart the ssh server yourself. On most distros
sudo systemctl restart sshdshould do it.
Worth noting this only affects the portable release of OpenSSH, so OpenBSD (or anyone else using the native release) are unaffected.