4.7

CVE-2021-24032: facebook zstandard Insecure Inherited Permissions

CVSS: 4.7v3.1MediumModified
AliasesALPINE-CVE-2021-24032MGASA-2021-0323UBUNTU-CVE-2021-24032
Published 04-03-2021Last modified 08-10-2026
Open JSON

Vulnerability summary

CVE-2021-24032 is a medium (CVSS 4.7) Insecure Inherited Permissions vulnerability in facebook zstandard. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.7/10
010
Medium · v3.1 (NVD)
EPSS score
0.35%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 4 · Related 4
OPENSUSE-SU-2021:0481-1SUSE-SU-2021:0948-1USN-4760-1USN-5720-1

Timeline

  1. 04-03-2021
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

0.00 pp

From 0.35% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.35%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Alpine1 product
  • zstd< 1.4.9-r0
Debian1 product
  • libzstd< 1.4.8+dfsg-2 | < 1.3.8+dfsg-3+deb10u2
Facebook1 product
  • zstandard≥ 1.4.1, < unspecified | ≥ 1.4.1, < 1.4.9
Mageia1 product
  • zstd< 1.4.8-1.1.mga8
Ubuntu1 product
  • libzstd< 1.3.1+dfsg-1~ubuntu0.16.04.1+esm3 | < 1.3.3+dfsg-2ubuntu1.2 | < 1.4.4+dfsg-3ubuntu0.1

5 vendors · 5 products

References

12 links
Show all 12 references