ChromeWeb browser · Google
CVE-2021-21111
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 · uneditedInsufficient policy enforcement in WebUI in Google Chrome prior to 87.0.4280.141 allowed an attacker who convinced a user to install a malicious extension to potentially perform a sandbox escape via a crafted Chrome Extension.
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 · moderate confidenceInsufficient policy enforcement in Chrome's WebUI allowed a malicious extension to potentially escape the sandbox. Attackers needed to convince users to install a crafted malicious extension, which could then bypass security policies to perform privileged operations. The vulnerability affected Chrome versions prior to 87.0.4280.141.
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
< 87.0.4280.141
FedoraOperating system
= 32= 33
Debian LinuxOperating system
= 10.0CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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 Chrome versionNavigate to chrome://settings/help or run 'google-chrome --version' in terminal to see the currently installed Chrome versionAffected if Version is less than 87.0.4280.141
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Check Chrome package version on FedoraRun 'rpm -qa | grep google-chrome' to see the installed Chrome package versionAffected if Package version is earlier than 87.0.4280.141-1
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Check Chrome package version on DebianRun 'dpkg -l | grep google-chrome' to see the installed Chrome package versionAffected if Package version is earlier than 87.0.4280.141-1
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Review installed extensionsNavigate to chrome://extensions/ and review all installed extensions. Check if any extension was installed from an untrusted or unknown sourceAffected if Any extension from an untrusted or suspicious source is installed, especially if Chrome version is vulnerable
User is affected if Chrome version is below 87.0.4280.141 and any extension from untrusted sources is installed, since the vulnerability allows a malicious extension to bypass security policies.
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 · scoped87.0.4280.141
Update Google Chrome to version 87.0.4280.141 or later. Organizations should also review extension policies and restrict extension installation to trusted sources only.
Chrome 87.0.4280.141 or later (or the latest stable channel release)
- Open Google Chrome and navigate to Settings > Help > About Google Chrome
- Click 'Update Google Chrome' if an update is available; Chrome will automatically update to version 87.0.4280.141 or later
- Restart the browser to complete the update
- Verify the update by returning to Settings > Help > About Google Chrome and confirming the version is 87.0.4280.141 or higher
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Chrome
Scoped from the published advisory
- Consultation1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21111 — 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-2021-21111 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