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CVE-2021-21166

76
FAUCET Score

CVE-2021-21166 is a high-severity data race vulnerability in the audio component of Google Chrome versions prior to 89.0.4389.72, affecting various Chrome distributions across Debian and Fedora. This flaw allows a remote unauthenticated attacker to trigger heap corruption by enticing a user to visit a specially crafted HTML page. With a CVSS score of 8.8, successful exploitation could lead to high impact on confidentiality, integrity, and availability. Notably, this vulnerability has been actively exploited in the wild, as confirmed by its presence in the CISA KEV catalog, and garnered significant community and media attention, despite the absence of publicly available exploit code in common repositories.

Impacted Technologies

VendorProductVersion(s)CPE
< 89.0.4389.72CPE matchmatch criteria
cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
32CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
10.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
23.85%
Probability of exploitation in next 30 days
EPSS Percentile
97.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Added to KEV · Nov 3, 2021
This CVE's current EPSS score of 0.2385 is in the 98th percentile among its peer group of 14,855 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.

Remediation

Vendor Advisories (1)

microsoft2021-Mar/CVE-2021-21166

Chromium CVE-2021-21166: Object lifecycle issue in audio

Mar 9, 2021

References

cisa.gov / known-exploited-vulnerabilities-catalog
US Government Resource
chromereleases.googleblog.com / 2021/03/stable-channel-update-for-desktop.html
Release Notes
crbug.com / 1177465
Permissions Required
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/BBT54RKAE5XLMWSHLVUKJ7T2XHHYMXLH
Release Notes
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/FE5SIKEVYTMDCC5OSXGOM2KRPYLHYMQX
Release Notes
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/LCIDZ77XUDMB2EBPPWCQXPEIJERDNSNT
Release Notes
security.gentoo.org / glsa/202104-08
Third Party Advisory
debian.org / security/2021/dsa-4886
Mailing ListThird Party Advisory