# CVE-2024-43102: umtx Kernel panic or Use-After-Free

> Concurrent removal of shared memory mappings causes a use-after-free, allowing kernel panics or code execution via sandbox escape.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/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:** 5 Sep 2024
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-v72r-7947-x8jx

## What is CVE-2024-43102?

CVE-2024-43102 is a critical use after free vulnerability in Freebsd Freebsd, published on 5 Sep 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of UMTX_OP_SHM can lead to decreasing the reference count of the object representing the mapping too many times, causing it to be freed too early.

A malicious code exercizing the UMTX_SHM_DESTROY sub-request in parallel can panic the kernel or enable further Use-After-Free attacks, potentially including code execution or Capsicum sandbox escape.

Weakness: CWE-911 (Improper Update of Reference Count), CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-43102?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2024-43102?

No fix has been published for CVE-2024-43102 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-43102 being exploited?

There is no known exploitation of CVE-2024-43102 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-2024-43102 and fix it if it is affected.

What it is: CVE-2024-43102 is a critical use after free vulnerability in Freebsd Freebsd, published on 5 Sep 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-2024-43102 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-2024-43102/ (Markdown: https://insights.sbomify.com/CVE-2024-43102/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43102
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43102
- OSV: https://osv.dev/vulnerability/CVE-2024-43102

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-43102/
Summaries are generated and may contain mistakes; the official description above is the record.