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ChromeWeb browser · Google

CVE-2021-21202

HIGH · 8.6 CVSS v3.1 Published 2021-04-26
Fix available
A fix is available. Upgrade to 90.0.4430.72 or later.
See remediation →
89/100
Remediation priority · High
No privileges

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 · unedited
Use after free in extensions in Google Chrome prior to 90.0.4430.72 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 · high confidence

A use-after-free vulnerability in Chrome's extensions subsystem allows a malicious Chrome extension to potentially escape the browser's sandbox. The vulnerability exists in versions prior to 90.0.4430.72 and requires user interaction (installing a malicious extension) to trigger.

MitigationUpdate Google Chrome to version 90.0.4430.72 or later. In enterprise environments, deploy the update via centralized endpoint management and verify compliance.

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
Affected:< 90.0.4430.72
Debian LinuxOperating system
Affected:= 10.0
FedoraOperating system
Affected:= 32= 33= 34

CVSS 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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Chrome version
    Navigate to chrome://settings/help or run 'google-chrome --version' in terminal
    Affected if Version number is less than 90.0.4430.72 (e.g., 89.x or earlier)
  2. Verify Chrome update status
    Open chrome://settings and check if 'Update Google Chrome' button is present at the bottom of the About section
    Affected if An update button exists, indicating the browser is not at the latest version
  3. Review installed extensions
    Navigate to chrome://extensions and examine all enabled extensions. Check for any unknown or suspicious extensions you did not intentionally install
    Affected if Any malicious or unwanted extension is installed and enabled
  4. Check browser auto-update status
    On Linux, verify the apt or dnf package manager shows chrome/chromium is at the vulnerable version: 'apt policy google-chrome-stable' (Debian) or 'dnf info google-chrome-stable' (Fedora)
    Affected if The packaged version in the distribution repository is below 90.0.4430.72

You are affected if Chrome version is below 90.0.4430.72 AND a malicious extension has been installed, as the vulnerability requires both conditions to be exploitable.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Upgrade available Upgrade to 90.0.4430.72 or later
Fixed in 90.0.4430.72
Interim mitigation

Update Google Chrome to version 90.0.4430.72 or later. In enterprise environments, deploy the update via centralized endpoint management and verify compliance.

Fix this in Chrome Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

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

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-21202 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

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.

What belongs here
  • 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