CVE-2021-21166
Google Chromium: Race Condition
As of , CVE-2021-21166 in Google Chromium is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch soon.
- Exploited
- Yes: CISA listed it on 3 November 2021
- US federal deadline
- 17 November 202114 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- EPSS score
- 0.24Higher than 97% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- EPSS when listed
- Not availableCISA listed it before 4 February 2022, where the EPSS files we read begin.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- No vendor link in CISA's entry
What CISA says to do
Apply updates per vendor instructions.
CISA's required action
What the flaw is
Google Chromium contains a race condition vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.
CISA's 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.
The CVE record's description, from Chrome
- CVE published
- 9 March 2021
- Assigned by
- Chrome
- CVSS
- 8.8 High (CVSS 3.1, from CISA-ADP)
- CWE-362
- Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- CWE-122
- Heap-based Buffer Overflow
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- no
- CISA SSVC, technical impact
- total
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Chromium: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2026-2441CSS Use-After-Free | Google Chromium | Patch this weekEPSS 0.55 | 0.55 | ||
| CVE-2025-14174Out of Bounds Memory Access | Google Chromium | Patch soon | 0.22 | ||
| CVE-2021-37976Information Disclosure | Google Chromium | Patch soon | 0.20 | ||
| CVE-2025-6558ANGLE and GPU Improper Input Validation | Google Chromium | Patch soon | 0.09 | ||
| CVE-2024-4671Visuals Use-After-Free | Google Chromium | Patch soon | 0.08 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org