# 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.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Aug 2024
- **Updated:** 16 Aug 2024
- **Also known as:** GHSA-j7jm-6q5x-ffr4

## 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.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-364 (Signal Handler Race Condition)

## Which versions are affected by CVE-2024-7589?

It affects 1 product.


Products: 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

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-7589 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2024-7589 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-7589/ (Markdown: https://insights.sbomify.com/CVE-2024-7589/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-7589
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-7589
- OSV: https://osv.dev/vulnerability/CVE-2024-7589

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-7589/
Summaries are generated and may contain mistakes; the official description above is the record.