CVE-2024-7589 OpenSSH pre-authentication async signal safety issue
An unauthenticated attacker can exploit a race condition in OpenSSH's signal handler to execute arbitrary code with root privileges on FreeBSD systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-7589?
CVE-2024-7589 is a high-severity vulnerability in Freebsd Freebsd, published on 11 Aug 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2024-7589?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2024-7589?
No fix has been published for CVE-2024-7589 yet. Limit exposure of the affected software until one is available.
Is CVE-2024-7589 being exploited?
There is no known exploitation of CVE-2024-7589 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-j7jm-6q5x-ffr4.