CVE-2021-24031

Name: CVE-2021-24031
Creator: NVD / NIST
Published: 2021-03-04T21:15:12.743+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.43%

Last modified Jun 17, 2026

CVE-2021-24031 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Zstandard command-line utility prior to v1.4.1, output files were created with default permissions. Correct file permissions (matching the input) would only be set at completion time. EPSS estimates a 0.43% chance of exploitation in the next 30 days.

Description

In the Zstandard command-line utility prior to v1.4.1, output files were created with default permissions. Correct file permissions (matching the input) would only be set at completion time. Output files could therefore be readable or writable to unintended parties.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.43%

34.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Facebook	Zstandard	< 1.4.1

References

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=981404Exploit, Issue Tracking, Mailing List, Third Party Advisory
https://github.com/facebook/zstd/issues/1630Exploit, Issue Tracking, Third Party Advisory
https://www.facebook.com/security/advisories/cve-2021-24031Vendor Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=981404Exploit, Issue Tracking, Mailing List, Third Party Advisory
https://github.com/facebook/zstd/issues/1630Exploit, Issue Tracking, Third Party Advisory
https://www.facebook.com/security/advisories/cve-2021-24031Vendor Advisory

Timeline

Published: Mar 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-24031?

How severe is CVE-2021-24031?

CVE-2021-24031 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2021-24031?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-24031?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST