# CVE-2015-6761: Race condition in n/a

> Remote attackers can cause denial of service or potential code execution via a crafted WebM file due to a race condition in FFmpeg's VP8 decoder.

- **Severity:** Medium 6.8 (`AV:N/AC:M/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 15 Oct 2015
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-6761, GHSA-w82p-vxv4-pvcf, UBUNTU-CVE-2015-6761

## What is CVE-2015-6761?

CVE-2015-6761 is a medium-severity vulnerability in Ffmpeg Ffmpeg, published on 15 Oct 2015. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The update_dimensions function in libavcodec/vp8.c in FFmpeg through 2.8.1, as used in Google Chrome before 46.0.2490.71 and other products, relies on a coefficient-partition count during multi-threaded operation, which allows remote attackers to cause a denial of service (race condition and memory corruption) or possibly have unspecified other impact via a crafted WebM file.

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

## Which versions are affected by CVE-2015-6761?

It affects 2 products.


Products: Ffmpeg Ffmpeg, Google Chrome.

## How do I fix CVE-2015-6761?

Upgrade to a fixed version.

## Is CVE-2015-6761 being exploited?

There is no known exploitation of CVE-2015-6761 in the wild and no public exploit code.

## Other vulnerabilities in Ffmpeg Ffmpeg

- [CVE-2013-0864](https://insights.sbomify.com/CVE-2013-0864/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-0872](https://insights.sbomify.com/CVE-2013-0872/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-0873](https://insights.sbomify.com/CVE-2013-0873/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-4265](https://insights.sbomify.com/CVE-2013-4265/): Null dereference in n/a (critical 10.0)
- [CVE-2011-3937](https://insights.sbomify.com/CVE-2011-3937/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-6761 and fix it if it is affected.

What it is: CVE-2015-6761 is a medium-severity vulnerability in Ffmpeg Ffmpeg, published on 15 Oct 2015. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2015-6761 in the wild and no public exploit code.

Affected product: Ffmpeg Ffmpeg. 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-2015-6761/ (Markdown: https://insights.sbomify.com/CVE-2015-6761/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-6761
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-6761
- OSV: https://osv.dev/vulnerability/CVE-2015-6761

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From sbomify Insights: https://insights.sbomify.com/CVE-2015-6761/
Summaries are generated and may contain mistakes; the official description above is the record.