CVE-2021-3185

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.

Published: 2021-01-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3185 is rated High Risk (69.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.38%). EPSS rose +1.71% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3185

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.67% 2.38% +1.71%
2 2025-11-21 1.51% 0.67% -0.84%
3 2025-11-18 — 1.51% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3185

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2021-3185

OS Trackers for CVE-2021-3185

vendor priority summary link
debian not yet assigned CVE-2021-3185 not yet assigned priority: Debian including 1 source packages (gst-plugins-bad1.0), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3185
gentoo high CVE-2021-3185: 1 GLSA(s) (202208-31), 6 atom(s) (media-libs/gst-plugins-bad, media-libs/gst-plugins-base, media-libs/gst-plugins-good, media-libs/gst-plugins-ugly, media-libs/gstreamer, media-plugins/gst-plugins-libav); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3185
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3185
suse high CVE-2021-3185 severity important: SUSE including 791 source package names (gstreamer-1.16.3-3.3.1, gstreamer-1.16.3-lp152.2.3.1, …), 1482 product×package rows across 62 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (62 product lines)): Fixed 1482. https://www.suse.com/security/cve/CVE-2021-3185/
ubuntu medium CVE-2021-3185 medium priority: Ubuntu including 1 source packages (gst-plugins-bad1.0), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 11, needed 3, ignored 1, released 1. https://ubuntu.com/security/CVE-2021-3185

Affected software / configurations for CVE-2021-3185

Vendor Product Version Raw CPE
freedesktop gst-plugins-bad < 1.18.1 cpe:2.3:a:freedesktop:gst-plugins-bad:*:*:*:*:*:*:*:*

References for CVE-2021-3185

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1917192 Issue Tracking Patch Third Party Advisory
https://security.gentoo.org/glsa/202208-31 Third Party Advisory
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