CVE-2021-21166
HighExploitedPublic exploitData race in audio in Google Chrome prior to 89.0.4389.72 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Published Dec 15, 2021 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2021-21166, TR-21-0193, TR-21-0220, UBUNTU-CVE-2021-21166
Key Facts
Patch immediately- CVE-2021-21166 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Chrome (Google), Debian Linux, Fedora (Fedoraproject) and 8 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Feb 11, 2021. Public exploit code is available.
- EPSS estimates a 24% probability of exploitation in the next 30 days.
- Fixed versions are available, including Chrome 89.0.4389.72, chromedriver 89.0.4389.72-bp152.2.62.1, chromedriver 89.0.4389.72-lp152.2.77.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
24%
Higher than 97.8% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-21166 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Data race in audio in Google Chrome prior to 89.0.4389.72 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | Nov 17, 2021 | Not reported |
| Industry KEV feed | Feb 11, 2021 | Nov 17, 2021 | Not reported |
| CIRCL KEV | Nov 3, 2021 | Nov 17, 2021 | Not reported |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
52 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ChromeGoogle | >= unspecified | 89.0.4389.72 |
| Debian LinuxDebian | 10.0 | n/a |
| FedoraFedoraproject | 32, 33, 34 | n/a |
| chromiumarch | See advisory | 89.0.4389.72-1 |
| operaarch | See advisory | 75.0.3969.149-1 |
Patched Releases
Chrome
89.0.4389.72
chromedriver
89.0.4389.72-bp152.2.62.1, 89.0.4389.72-lp152.2.77.1, 93.0.4577.82-1.1
chromium
89.0.4389.114-1~deb10u1, 89.0.4389.72-1, 89.0.4389.72-bp152.2.62.1, 89.0.4389.72-lp152.2.77.1, 89.0.4389.72-r0, 89.0.4389.82-1, 93.0.4577.82-1.1
chromium-browser
89.0.4389.82-0ubuntu0.16.04.1, 89.0.4389.82-0ubuntu0.18.04.1
opera
75.0.3969.149-1
qt5-qtwebengine
5.15.3_git20200401-r0
ungoogled-chromium
113.0.5672.92-1.1
ungoogled-chromium-chromedriver
113.0.5672.92-1.1
vivaldi
3.7.2218.45-1
Timeline
Added to Industry KEV feed
Feb 11, 2021
Added to CISA KEV
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Publicly disclosed
Dec 15, 2021
Last updated
Aug 4, 2026
Weakness Type
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
References
- advisoryhttps://chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop_12.html
- advisoryhttps://chromereleases.googleblog.com/2021/12/stable-channel-update-for-desktop_13.html
- advisoryhttps://gbhackers.com/google-zero-day-vulnerability/
- advisoryhttps://indianexpress.com/article/technology/tech-news-technology/google-chrome-releases-emergency-update-to-fix-multiple-security-vulnerabilities-7673638/
- advisoryhttps://securityaffairs.co/wordpress/115600/security/google-chrome-0-day.html?utm_source=rss&utm_medium=rss&utm_campaign=google-chrome-0-day
FAQ
Common Questions.
Data race in audio in Google Chrome prior to 89.0.4389.72 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Affected: Chrome (Google) versions >= unspecified; Debian Linux versions 10.0; Fedora (Fedoraproject) versions 32, 33, 34, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Feb 11, 2021.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of Nov 17, 2021.
Public exploit code is available.
Fixed versions are available, including Chrome 89.0.4389.72, chromedriver 89.0.4389.72-bp152.2.62.1, chromedriver 89.0.4389.72-lp152.2.77.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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