ChromeWeb browser · Google
CVE-2021-30549
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 Spell check in Google Chrome prior to 91.0.4472.101 allowed an attacker who convinced a user to install a malicious extension 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 confidenceUse-after-free vulnerability in Google Chrome's Spell Check component prior to version 91.0.4472.101. An attacker could exploit this by tricking a user into installing a malicious extension that triggers the vulnerability through a crafted HTML page, potentially leading to heap corruption and arbitrary code execution.
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.
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Check installed Google Chrome versionOpen chrome://settings/help or run 'google-chrome --version' in terminalAffected if version is lower than 91.0.4472.101
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Check if Spell Check is enabledNavigate to chrome://settings/languages and verify if 'Spell check' toggle is turned onAffected if Spell Check feature is enabled and Chrome version is below 91.0.4472.101
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Review installed extensionsNavigate to chrome://extensions and examine all installed extensionsAffected if any untrusted or suspicious extensions are present alongside a vulnerable Chrome version
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Check Fedora package version (if applicable)Run 'rpm -qa | grep -i chrome' or 'dnf list installed | grep -i chrome' to list installed Chrome packagesAffected if Fedora version is 33 or 34 and the installed chrome package version is below 91.0.4472.101
The environment is affected if Google Chrome (or the Fedora chrome package) version is below 91.0.4472.101 AND the Spell Check feature is enabled.
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. Review and restrict browser extensions to only those from trusted sources to prevent malicious extension installation.
Chrome 91.0.4472.101 or later (stable release)
- Open Chrome and navigate to Settings > Help > About Google Chrome to check current version
- If version is below 91.0.4472.101, download and install the latest stable Chrome from chrome.com or update via your system's package manager
- For Fedora systems: run 'sudo dnf update google-chrome-stable' to update to the fixed package
- Restart Chrome after the update completes
- Verify the version now shows 91.0.4472.101 or later via Settings > Help > About Google Chrome
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Chrome
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 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 $1,744.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30549 — 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-2021-30549 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