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Fencer Vulns
medium 5.5

CVE-2021-4214 json

A heap overflow flaw was found in libpngs' pngimage.c program.

published 2022-08-24 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34072

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

A heap overflow flaw was found in libpngs' pngimage.c program. This flaw allows an attacker with local network access to pass a specially crafted PNG file to the pngimage utility, causing an application to crash, leading to a denial of service.

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-2021-4214 updated cvss 5.5

libpng: hardcoded value leads to heap-overflow

  • Red Hat Enterprise Linux 5 libpng Red Hat Enterprise Linux 6 libpng Red Hat Enterprise Linux 7 libpng Red Hat Enterprise Linux 8 libpng Red Hat Enterprise Linux 9 libpng
    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

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/glennrp/libpng/issues/302 referenced PoC, tagged "exploit" by a source, unverified
  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=2043393 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • n/a libpng

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input
  • CWE-787 Out-of-bounds Write

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.