# CVE-2024-36621: Moby Race Condition vulnerability

> Attackers can trigger concurrent builds to cause resource exhaustion and denial of service in Docker Engine.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 29 Nov 2024
- **Updated:** 4 Dec 2024
- **Also known as:** AZL-53810, AZL-53813, DEBIAN-CVE-2024-36621, GHSA-2mj3-vfvx-fc43, GO-2024-3304, OESA-2024-2525, OESA-2024-2528, OESA-2024-2529, UBUNTU-CVE-2024-36621

## What is CVE-2024-36621?

CVE-2024-36621 is a medium-severity vulnerability in n/a, published on 29 Nov 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

moby v25.0.5 is affected by a Race Condition in builder/builder-next/adapters/snapshot/layer.go. The vulnerability could be used to trigger concurrent builds that call the EnsureLayer function resulting in resource leaks/exhaustion.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2024-36621?

3 open source packages ship an affected version, including github.com/moby/moby. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/moby/moby` | Go | All versions | 26.0.0 |
| `github.com/moby/moby` | Go | All versions | 26.0.0 |
| `github.com/moby/moby` | Go | All versions | 26.0.0+incompatible |

Products: Mobyproject Moby.

## How do I fix CVE-2024-36621?

Upgrade github.com/moby/moby to a fixed version for your release line: 26.0.0 or 26.0.0+incompatible.

## Is CVE-2024-36621 being exploited?

There is no known exploitation of CVE-2024-36621 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2024-36623](https://insights.sbomify.com/CVE-2024-36623/): Moby Race Condition vulnerability (high 8.1)
- [CVE-2023-28840](https://insights.sbomify.com/CVE-2023-28840/): moby/moby's dockerd daemon encrypted overlay network may be unauthenticated (high 7.5)
- [CVE-2018-12608](https://insights.sbomify.com/CVE-2018-12608/): Docker Authentication Bypass (high 7.5)
- [CVE-2024-24557](https://insights.sbomify.com/CVE-2024-24557/): Moby classic builder cache poisoning (medium 6.9)
- [CVE-2023-28841](https://insights.sbomify.com/CVE-2023-28841/): moby/moby's dockerd daemon encrypted overlay network traffic may be unencrypted (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-36621 and fix it if it is affected.

What it is: CVE-2024-36621 is a medium-severity vulnerability in n/a, published on 29 Nov 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-2024-36621 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/moby/moby (Go): affected all versions; fixed in 26.0.0
- github.com/moby/moby (Go): affected all versions; fixed in 26.0.0
- github.com/moby/moby (Go): affected all versions; fixed in 26.0.0+incompatible

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-2024-36621/ (Markdown: https://insights.sbomify.com/CVE-2024-36621/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36621
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36621
- OSV: https://osv.dev/vulnerability/CVE-2024-36621

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36621/
Summaries are generated and may contain mistakes; the official description above is the record.