CVE-2021-24031 Information disclosure in Zstandard
Local attackers can read or modify Zstandard output files due to insecure default permissions before completion.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-24031?
CVE-2021-24031 is a medium-severity vulnerability in Facebook Zstandard, published on 4 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2021-24031?
It affects 1 product.
Products include Facebook Zstandard.
How do I fix CVE-2021-24031?
Upgrade to a fixed version.
Is CVE-2021-24031 being exploited?
There is no known exploitation of CVE-2021-24031 in the wild and no public exploit code.
Other vulnerabilities in Facebook Zstandard
Sources
Also known as ALPINE-CVE-2021-24031, CLEANSTART-2025-NH78236, DEBIAN-CVE-2021-24031, DLA-2573-1, DSA-4850-1, GHSA-5mqj-v3fr-pg3x and 2 more.