# CVE-2024-12084: Rsync: heap buffer overflow in rsync due to improper checksum length handling

> Heap buffer overflow in rsync daemon allows attackers to execute arbitrary code or cause denial of service via crafted checksum lengths.

- **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:** Yes
- **Published:** 15 Jan 2025
- **Updated:** 21 Oct 2026
- **Also known as:** ALPINE-CVE-2024-12084, AZL-55646, AZL-55691, BELL-CVE-2024-12084, DEBIAN-CVE-2024-12084, GHSA-85h7-m8c3-v9wc, UBUNTU-CVE-2024-12084

## What is CVE-2024-12084?

CVE-2024-12084 is a critical memory corruption vulnerability in Gentoo Linux, published on 15 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A heap-based buffer overflow flaw was found in the rsync daemon. This issue is due to improper handling of attacker-controlled checksum lengths (s2length) in the code. When MAX_DIGEST_LEN exceeds the fixed SUM_LENGTH (16 bytes), an attacker can write out of bounds in the sum2 buffer.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2024-12084?

It affects 8 products.


Products: Almalinux Almalinux, Archlinux Arch Linux, Gentoo Linux, Nixos Nixos, Novell Suse Linux, Redhat Enterprise Linux, Samba Rsync, Tritondatacenter Smartos.

## How do I fix CVE-2024-12084?

Apply the vendor's patch.

## Is CVE-2024-12084 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-12084 exists.

Public exploit code:

- https://github.com/themirze/cve-2024-12084 (github_poc): https://github.com/themirze/cve-2024-12084
- A heap-based buffer overflow flaw was found in the rsync daemon. This issue is due to improper handling of attacker-controlled checksum lengths (s2length) in the code. When MAX_DIGEST_LEN exceeds the fixed SUM_LENGTH (16 bytes), an attacker can write out of bounds in the sum2 buffer. (github_poc): https://github.com/rxerium/CVE-2024-12084
- A easy poc for CVE-2024-12084. (github_poc): https://github.com/InkeyP/CVE-2024-12084

## Other vulnerabilities in Gentoo Linux

- [CVE-2024-6387](https://insights.sbomify.com/CVE-2024-6387/): Openssh: regresshion - race condition in ssh allows rce/dos (high 8.1)
- [CVE-2024-12085](https://insights.sbomify.com/CVE-2024-12085/): Rsync: info leak via uninitialized stack contents (high 7.5)
- [CVE-2024-12087](https://insights.sbomify.com/CVE-2024-12087/): Rsync: path traversal vulnerability in rsync (medium 6.5)
- [CVE-2024-12088](https://insights.sbomify.com/CVE-2024-12088/): Rsync: --safe-links option bypass leads to path traversal (medium 6.5)
- [CVE-2024-12086](https://insights.sbomify.com/CVE-2024-12086/): Rsync: rsync server leaks arbitrary client files (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-12084 and fix it if it is affected.

What it is: CVE-2024-12084 is a critical memory corruption vulnerability in Gentoo Linux, published on 15 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-12084 exists.

Affected product: Gentoo Linux. 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-2024-12084/ (Markdown: https://insights.sbomify.com/CVE-2024-12084/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-12084
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-12084
- OSV: https://osv.dev/vulnerability/CVE-2024-12084

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-12084/
Summaries are generated and may contain mistakes; the official description above is the record.