# CVE-2018-5766: Memory corruption in n/a

> Remote attackers can cause a denial of service via segmentation fault by exploiting an invalid memcpy in Libav with a crafted AVI file.

- **Severity:** High 8.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Jan 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-mhfv-c2x6-4jxx, UBUNTU-CVE-2018-5766

## What is CVE-2018-5766?

CVE-2018-5766 is a high-severity memory corruption vulnerability in Libav Libav, published on 18 Jan 2018. 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

In Libav through 12.2, there is an invalid memcpy in the av_packet_ref function of libavcodec/avpacket.c. Remote attackers could leverage this vulnerability to cause a denial of service (segmentation fault) via a crafted avi file.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2018-5766?

It affects 1 product.


Products: Libav Libav.

## How do I fix CVE-2018-5766?

Upgrade to a fixed version.

## Is CVE-2018-5766 being exploited?

There is no known exploitation of CVE-2018-5766 in the wild and no public exploit code.

## Other vulnerabilities in Libav Libav

- [CVE-2014-3984](https://insights.sbomify.com/CVE-2014-3984/): Multiple unspecified vulnerabilities in Libav before 0.8.12 allow remote attackers to have unknown impact and vectors. (critical 10.0)
- [CVE-2017-9051](https://insights.sbomify.com/CVE-2017-9051/): Null dereference in n/a (critical 9.8)
- [CVE-2014-4609](https://insights.sbomify.com/CVE-2014-4609/): Integer overflow in n/a (high 8.8)
- [CVE-2019-9719](https://insights.sbomify.com/CVE-2019-9719/): Memory corruption in n/a (high 8.8)
- [CVE-2018-5684](https://insights.sbomify.com/CVE-2018-5684/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-5766 and fix it if it is affected.

What it is: CVE-2018-5766 is a high-severity memory corruption vulnerability in Libav Libav, published on 18 Jan 2018. 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-2018-5766 in the wild and no public exploit code.

Affected product: Libav Libav. 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-2018-5766/ (Markdown: https://insights.sbomify.com/CVE-2018-5766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-5766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-5766
- OSV: https://osv.dev/vulnerability/CVE-2018-5766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-5766/
Summaries are generated and may contain mistakes; the official description above is the record.