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NVD / CVE Program· CNA redhat

CVE-2021-4156: An out-of-bounds read flaw was found in libsndfile's FLAC codec functionality.

Noroxi assessment

Priority: Monitor (action score 29/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.7% (FIRST EPSS); higher than 77.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: libsndfile (AlmaLinux:8) 1.0.28-12.el8; libsndfile-devel (AlmaLinux:8) 1.0.28-12.el8; libsndfile (Debian:10) 1.0.28-6+deb10u2.

Low priority for now. Upgrade to libsndfile (AlmaLinux:8) 1.0.28-12.el8; libsndfile-devel (AlmaLinux:8) 1.0.28-12.el8; libsndfile (Debian:10) 1.0.28-6+deb10u2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An out-of-bounds read flaw was found in libsndfile's FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws.

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
Mar 23, 2022
Updated
Jun 17, 2026
EPSS
1.7% · 77th percentile

Report tools

JSON

Action score

29

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.7%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
libsndfile projectlibsndfile
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux10.0
  • debian debian linux9.0
  • libsndfile project libsndfile1.1.10

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a libsndfile

    • libsndfile 1.1.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8libsndfilebefore 1.0.28-12.el81.0.28-12.el8
AlmaLinux:8libsndfile-develbefore 1.0.28-12.el81.0.28-12.el8
Debian:10libsndfilebefore 1.0.28-6+deb10u21.0.28-6+deb10u2
Debian:11libsndfilebefore 1.0.31-2+deb11u21.0.31-2+deb11u2
Debian:12libsndfilebefore 1.1.0-11.1.0-1
Debian:9libsndfilebefore 1.0.27-3+deb9u31.0.27-3+deb9u3
openSUSE:Leap 15.3libsndfilebefore 1.0.28-5.15.11.0.28-5.15.1
openSUSE:Leap 15.3libsndfile-progsbefore 1.0.28-5.15.11.0.28-5.15.1
openSUSE:Tumbleweedlibsndfilebefore 1.0.31-3.11.0.31-3.1
Red Hat:enterprise_linux:8::appstreamlibsndfilebefore 0:1.0.28-12.el80:1.0.28-12.el8
Red Hat:enterprise_linux:8::appstreamlibsndfile-debuginfobefore 0:1.0.28-12.el80:1.0.28-12.el8
Red Hat:enterprise_linux:8::appstreamlibsndfile-debugsourcebefore 0:1.0.28-12.el80:1.0.28-12.el8
Red Hat:enterprise_linux:8::appstreamlibsndfile-utils-debuginfobefore 0:1.0.28-12.el80:1.0.28-12.el8
Red Hat:enterprise_linux:8::crblibsndfile-develbefore 0:1.0.28-12.el80:1.0.28-12.el8
Rocky Linux:8libsndfilebefore 0:1.0.28-12.el80:1.0.28-12.el8
SUSE:HPE Helion OpenStack 8libsndfilebefore 1.0.25-36.26.11.0.25-36.26.1
SUSE:Linux Enterprise Module for Basesystem 15 SP3libsndfilebefore 1.0.28-5.15.11.0.28-5.15.1
SUSE:Linux Enterprise Point of Sale 11 SP3libsndfilebefore 1.0.20-2.19.18.11.0.20-2.19.18.1

Same product

libsndfile project: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-12562Heap-based Buffer Overflow in the psf_binheader_writef function in common.c in libsndfile through 1.0.28 allows remote attackers to cause a
    40Plan
  • CVE-2021-3246A heap buffer overflow vulnerability in msadpcm_decode_block of libsndfile 1.0.30 allows attackers to execute arbitrary code via a crafted W
    36Monitor
  • CVE-2018-13139A stack-based buffer overflow in psf_memset in common.c in libsndfile 1.0.28 allows remote attackers to cause a denial of service (applicati
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2018-19758Nov 29, 2018 · There is a heap-based buffer over-read at wav.c in wav_write_header in libsndfile 1.0.28 that will cause a denial of service.
    27Monitor
  • ← EarlierCVE-2019-3832Mar 21, 2019 · It was discovered the fix for CVE-2018-19758 (libsndfile) was not complete and still allows a read beyond the limits of a buffer in wav_writ
    22Monitor
  • Later →CVE-2022-33064Jul 18, 2023 · An off-by-one error in function wav_read_header in src/wav.c in Libsndfile 1.1.0, results in a write out of bound, which allows an attacker
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:libsndfile1.0.28-12.el8 · AlmaLinux:8Package registry (OSV)
almalinux:libsndfile-devel1.0.28-12.el8 · AlmaLinux:8Package registry (OSV)
debian:libsndfile1.1.0-1 · Debian:12Package registry (OSV)
opensuse:libsndfile1.0.28-5.15.1 · openSUSE:Leap 15.3Package registry (OSV)
opensuse:libsndfile-progs1.0.28-5.15.1 · openSUSE:Leap 15.3Package registry (OSV)
red hat:libsndfile0:1.0.28-12.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libsndfile-debuginfo0:1.0.28-12.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libsndfile-debugsource0:1.0.28-12.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libsndfile-devel0:1.0.28-12.el8 · Red Hat:enterprise_linux:8::crbPackage registry (OSV)
red hat:libsndfile-utils-debuginfo0:1.0.28-12.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
rocky linux:libsndfile0:1.0.28-12.el8 · Rocky Linux:8Package registry (OSV)
suse:libsndfile1.0.25-36.26.1 · SUSE:HPE Helion OpenStack 8Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records