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Fencer Vulns
critical 9.8

CVE-2021-3185 json

A flaw was found in the gstreamer h264 component of gst-plugins-bad before v1.18.1 where when parsing a h264 header, an attacker could caus…

published 2021-01-25 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26528

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.5%
EPSS 2.5% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

A flaw was found in the gstreamer h264 component of gst-plugins-bad before v1.18.1 where when parsing a h264 header, an attacker could cause the stack to be smashed, memory corruption and possibly code execution.

Patch / fix

  • freedesktop gst-plugins-bad 1.18.1
  • gst-plugins-bad1.0 Debian 14, Debian 13, Debian 12 1.18.1-1

debian advisories DEBIAN-CVE-2021-3185

  • gstreamer-plugins-bad SLE Module for Desktop Applications 15 SP3, SLE Module for Basesystem 15 SP3 1.16.3-9.3.1
  • gstreamer-plugins-bad SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +10 more 1.12.5-3.6.1
  • gstreamer-plugins-bad SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 1.8.3-18.3.5
  • gstreamer-plugins-bad SLES 12 SP2-BCL 1.2.4-3.7.1
  • gstreamer-plugins-ugly SLE Workstation Extension 15 SP3, SLE Workstation Extension 15 SP2 1.16.3-3.3.1
  • gstreamer SLE Module for Package Hub 15 SP3, SLE Module for Package Hub 15 SP2, SLE Module for Desktop Applications 15 SP2 +3 more 1.16.3-3.3.1
  • gstreamer-plugins-bad SLE Module for Desktop Applications 15 SP2, SLE Module for Basesystem 15 SP2 1.16.3-4.4.1
  • gstreamer-plugins-base SLE Module for Package Hub 15 SP3, SLE Module for Package Hub 15 SP2, SLE Module for Desktop Applications 15 SP2 +3 more 1.16.3-4.3.1

suse advisories SUSE-SU-2021:1944-1SUSE-SU-2021:1904-1SUSE-SU-2021:1875-1SUSE-SU-2021:1873-1SUSE-SU-2021:1819-1

  • gstreamer-plugins-ugly openSUSE Leap 15.3 1.16.3-3.3.1
  • gstreamer openSUSE Leap 15.3 1.16.3-3.3.1
  • gstreamer-plugins-base openSUSE Leap 15.3 1.16.3-4.3.1
  • gstreamer-plugins-good openSUSE Leap 15.3 1.16.3-3.3.1
  • gstreamer-plugins-bad openSUSE Leap 15.3 1.16.3-lp153.3.3.1
  • gstreamer-plugins-ugly openSUSE Leap 15.2 1.16.3-lp152.2.3.1
  • gstreamer openSUSE Leap 15.2 1.16.3-lp152.2.3.1
  • gstreamer-plugins-bad openSUSE Leap 15.2 1.16.3-lp152.3.3.1

opensuse advisories openSUSE-SU-2021:1819-1openSUSE-SU-2021:1012-1openSUSE-SU-2021:0822-1

  • gst-plugins-bad Arch Linux 1.18.0+54+gbd3532008-1

arch linux advisories AVG-1484

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-2021-3185 updated cvss 7.3

gstreamer: buffer overflow in gst_h264_slice_parse_dec_ref_pic_marking

  • Red Hat Enterprise Linux 5 gstreamer-plugins-bad-free Red Hat Enterprise Linux 6 gstreamer-plugins-bad-free, gstreamer-plugins-bad-free-extras
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 gstreamer-plugins-bad-free Red Hat Enterprise Linux 8 gstreamer1-plugins-bad-free
    affected: no fix planned “Will not fix”

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

2.48% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • n/a gstreamer

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.