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Public proof of conceptFix available

CVE-2021-40426

A public proof of concept exists; no exploitation attested.

  • Published2022-04-14
  • WeaknessCWE-122 · CWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A heap-based buffer overflow vulnerability exists in the sphere.c start_read() functionality of Sound Exchange libsox 14.4.2 and master commit 42b3557e. A specially-crafted file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.

Timeline

dates in UTC
  1. 2022-04-1420:15CVE publishedNVD

Versions per branch

NVD
Sound exchange project sound exchange
BranchAffectedFixed in
14.4= 14.4.2no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As talos, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Sound Exchange libsox
    Affected
    • = 14.4.2no fix stated
    • = master commit 42b3557eno fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2023-02-22

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • soxUbuntu:Pro:16.04:LTSall versions · fixed in 14.4.1-5+deb8u4ubuntu0.1+esm1
  • soxUbuntu:Pro:14.04:LTSall versions · fixed in 14.4.1-3ubuntu1.1+esm2
  • soxUbuntu:22.04:LTSall versions · fixed in 14.4.2+git20190427-2+deb11u1build0.22.04.1
  • soxUbuntu:20.04:LTSall versions · fixed in 14.4.2+git20190427-2+deb11u1build0.20.04.1
  • soxUbuntu:18.04:LTSall versions · fixed in 14.4.2-3ubuntu0.18.04.2
  • soxSUSE:Package Hub 15 SP5all versions · fixed in 14.4.2-bp155.3.3.1
  • soxSUSE:Package Hub 15 SP4all versions · fixed in 14.4.2-bp154.2.3.1
  • soxopenSUSE:Tumbleweedall versions · fixed in 14.4.2-8.1

15 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-40426 Red Hat Product Security5 known affected

    sox: heap-based buffer overflow vulnerability exists in the sphere.c start_read() function

    sox as a component of Red Hat Enterprise Linux 6 · sox-devel as a component of Red Hat Enterprise Linux 6 · sox as a component of Red Hat Enterprise Linux 7 · +2 more

Full record on NVD

Fix

  1. No fix planned, says the vendor Red Hat Product Security CVE-2021-40426 · 5 productsOut of support scope

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionpoc2025-04-15
  • NVDCVSS 3.18.8read 2026-10-23
  • CNACVSS 3.010known since 2026-10-23
  • NVDCVSS 2.06.8read 2026-10-23
  • CNAweakness (CWE)CWE-122known since 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score2.1 %2026-11-08
  • OSVaffected packages—
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2022-04-14
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-5x4j-m9qh-g9w5

Frequently asked questions

What is CVE-2021-40426?

A heap-based buffer overflow vulnerability exists in the sphere.c start_read() functionality of Sound Exchange libsox 14.4.2 and master commit 42b3557e. A specially-crafted file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.

Is CVE-2021-40426 actively exploited?

A proof-of-concept exploit exists for CVE-2021-40426, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2021-40426?

CVE-2021-40426 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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