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Fencer Vulns
medium 4.7

CVE-2021-24032 json

Beginning in v1.4.1 and prior to v1.4.9, due to an incomplete fix for CVE-2021-24031, the Zstandard...

published 2021-03-04 5 y ago modified 2026-10-08 31 d ago also EUVD-2021-10952 , GHSA-ffqj-7pgc-cmj5 , JLSEC-2026-121

cvss
4.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia Zstd_jll 1.5.0+0
  • facebook zstandard 1.4.9
  • libzstd Debian 14, Debian 13, Debian 12 1.4.8+dfsg-2

debian advisories DEBIAN-CVE-2021-24032

  • libzstd Ubuntu 18.04 LTS 1.3.3+dfsg-2ubuntu1.2
  • libzstd Ubuntu 20.04 LTS 1.4.4+dfsg-3ubuntu0.1
  • libzstd Ubuntu Pro 16.04 LTS 1.3.1+dfsg-1~ubuntu0.16.04.1+esm3

ubuntu advisories UBUNTU-CVE-2021-24032

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • zstd SLE Module for Basesystem 15 SP2, SLE Micro 5.0 1.4.4-1.6.1

suse advisories SUSE-SU-2021:0948-1

  • zstd openSUSE Leap 15.2 1.4.4-lp152.2.3.1

opensuse advisories openSUSE-SU-2021:0481-1

  • zstd Alpine 3.24, Alpine 3.23, Alpine 3.22 +11 more 1.4.9-r0

alpine advisories ALPINE-CVE-2021-24032

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ceph Azure Linux 3.0 18.2.2-5
  • ceph CBL-Mariner 2.0 16.2.10-3

azure linux advisories AZL-38944AZL-39352

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

  • zstd Arch Linux 1.4.9-1

arch linux advisories AVG-1627

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-24032 updated cvss 5.5

zstd: Race condition allows attacker to access world-readable destination file

  • Red Hat Advanced Cluster Security 3 rox
    affected: no fix available
  • Red Hat Ceph Storage 3 ceph, librbd1, librgw2, ceph-mds, ceph-mgr, ceph-mon, +15 more
    affected: no fix available “Fix deferred”
  • Red Hat Ceph Storage 7 libzstd
    affected: no fix available
  • Red Hat Enterprise Linux 8 zstd, libzstd
    affected: no fix available “Fix deferred”
  • Red Hat OpenShift Container Platform 4 zstd, libzstd
    affected: no fix planned “Out of support scope”
  • Red Hat AMQ Streams 2.7.0
    fixed: vendor fix RHSA-2024:3527
  • Red Hat Enterprise Linux 9 zstd, libzstd Red Hat OpenStack Platform 16.1 zstd
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
31 d ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 1.9 AV:L/AC:M/Au:N/C:P/I:N/A:N
OSV 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia Zstd_jll
<1.5.0+0
1.5.0+0

Affected products

  • Facebook Zstandard

Classification

Weakness
  • CWE-277 Insecure Inherited Permissions
  • CWE-276 Incorrect Default Permissions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.