ChromeWeb browser · Google
CVE-2021-30544
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUse after free in BFCache in Google Chrome prior to 91.0.4472.101 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA use-after-free vulnerability exists in Chrome's Back-Forward Cache (BFCache) implementation. The BFCache stores complete page snapshots for faster back/forward navigation, but the vulnerability allows a crafted HTML page to trigger a dangling pointer that persists after the cached object is freed, enabling heap corruption when the freed memory is accessed.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
ChromeWeb browser
< 91.0.4472.101
FedoraOperating system
= 33= 34CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check Google Chrome versionOpen Chrome and navigate to chrome://version, or run 'google-chrome --version' or 'chromium-browser --version' in terminalAffected if The version displayed is less than 91.0.4472.101
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Check Fedora release versionRun 'cat /etc/fedora-release' in terminalAffected if The output shows Fedora 33 or Fedora 34 AND Chrome version is below 91.0.4472.101
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Confirm BFCache is in useThe Back-Forward Cache is enabled by default in affected Chrome versions; navigate to a website, go to another page, then use the browser back button to trigger back/forward navigationAffected if The browser version is vulnerable AND back/forward navigation is used, allowing the BFCache use-after-free to be triggered
You are affected if you are running Google Chrome or Chromium-based browsers with version lower than 91.0.4472.101 on Fedora 33 or 34, or any system with Chrome versions below 91.0.4472.101.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped91.0.4472.101
Update Google Chrome to version 91.0.4472.101 or later to patch the BFCache use-after-free vulnerability.
Chrome 91.0.4472.101 or later (Fedora: chromium-91.0.4472.101-1 or later / google-chrome-stable-91.0.4472.101-1 or later)
- Open Google Chrome
- Navigate to Settings > Help > About Google Chrome
- Chrome will automatically check for and install the latest version
- Ensure the installed version is 91.0.4472.101 or later
- For Fedora systems, run: sudo dnf update chromium or sudo dnf update google-chrome-stable
- Restart the browser after updating
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Chrome
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30544 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-30544 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data