# CVE-2024-9143: Low-level invalid GF(2^m) parameters lead to OOB memory access

> Attackers can trigger out-of-bounds memory access in OpenSSL when using low-level APIs with invalid GF(2^m) curve parameters, potentially causing crashes or remote code execution.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Oct 2024
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2024-9143, AZL-78531, BELL-CVE-2024-9143, CLEANSTART-2026-QL44288, DEBIAN-CVE-2024-9143, GHSA-q764-r57m-9wp9, JLSEC-2026-254, MGASA-2024-0354, MGASA-2024-0355, MINI-xxrx-crr8-74g3, OESA-2024-2384, OESA-2024-2385, OESA-2024-2386, OESA-2024-2387, OESA-2024-2480, OESA-2025-1352, UBUNTU-CVE-2024-9143

## What is CVE-2024-9143?

CVE-2024-9143 is a medium-severity memory corruption vulnerability in OpenSSL, published on 16 Oct 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Issue summary: Use of the low-level GF(2^m) elliptic curve APIs with untrusted
explicit values for the field polynomial can lead to out-of-bounds memory reads
or writes.

Impact summary: Out of bound memory writes can lead to an application crash or
even a possibility of a remote code execution, however, in all the protocols
involving Elliptic Curve Cryptography that we're aware of, either only "named
curves" are supported, or, if explicit curve parameters are supported, they
specify an X9.62 encoding of binary (GF(2^m)) curves that can't represent
problematic input values. Thus the likelihood of existence of a vulnerable
application is low.

In particular, the X9.62 encoding is used for ECC keys in X.509 certificates,
so problematic inputs cannot occur in the context of processing X.509
certificates.  Any problematic use-cases would have to be using an "exotic"
curve encoding.

The affected APIs include: EC_GROUP_new_curve_GF2m(), EC_GROUP_new_from_params(),
and various supporting BN_GF2m_*() functions.

Applications working with "exotic" explicit binary (GF(2^m)) curve parameters,
that make it possible to represent invalid field polynomials with a zero
constant term, via the above or similar APIs, may terminate abruptly as a
result of reading or writing outside of array bounds.  Remote code execution
cannot easily be ruled out.

The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2024-9143?


## How do I fix CVE-2024-9143?

Apply the vendor's patch.

## Is CVE-2024-9143 being exploited?

There is no known exploitation of CVE-2024-9143 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-9143 and fix it if it is affected.

What it is: CVE-2024-9143 is a medium-severity memory corruption vulnerability in OpenSSL, published on 16 Oct 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-9143 in the wild and no public exploit code.

Affected product: OpenSSL. 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-2024-9143/ (Markdown: https://insights.sbomify.com/CVE-2024-9143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-9143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-9143
- OSV: https://osv.dev/vulnerability/CVE-2024-9143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-9143/
Summaries are generated and may contain mistakes; the official description above is the record.