CVE-2021-21220
Out-of-bounds Write: Is CVE-2021-21220 real, exploitable, or a false positive? Here's the community verdict.
signals
public sources
Confirmed exploited in the wild. Patch this first, regardless of the base score.
public exploits
links to sources — we don’t host codeA working exploit is publicly available from a maintained source. Treat this as higher urgency and verify your exposure.
baseline read
auto · not a community verdict
Real — exploited in the wild
CISA confirms active exploitation. Treat scanner hits as true positives unless your specific version or config is unaffected.
Based on CISA KEV
Confirm or dispute →CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
References
Published
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Community ground truth
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In your experience, is this finding real and exploitable?
awaiting field verdictsCurated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.
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Field notes & remediation
Verdicts are the quick signal. Notes are the evidence and fixes behind them.
- 0
Google Chromium V8 Improper Input Validation Vulnerability — Google Chromium V8 Engine contains an improper input validation 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. Listed in the CISA KEV catalog (added 2021-11-03) — confirmed exploited in the wild, not theoretical. FIRST EPSS puts the chance of exploitation in the next 30 days at ~70%. Treat it as real and prioritize remediation over triage.
- 0
Required action for Google Chromium V8: Apply updates per vendor instructions. CISA set a federal remediation due date of 2021-11-17. After patching, verify the vulnerable path is no longer reachable before closing the finding.
Add a field note or remediationoptional
Related CVEs
Same weakness: CWE-787 · Out-of-bounds Write.
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