FirefoxWeb browser · Mozilla
CVE-2022-1802
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 · uneditedIf an attacker was able to corrupt the methods of an Array object in JavaScript via prototype pollution, they could have achieved execution of attacker-controlled JavaScript code in a privileged context. This vulnerability affects Firefox ESR < 91.9.1, Firefox < 100.0.2, Firefox for Android < 100.3.0, and Thunderbird < 91.9.1.
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 confidenceThis is a prototype pollution vulnerability in Firefox and Thunderbird's JavaScript engine. If an attacker corrupts the methods of an Array object through prototype pollution, they can achieve execution of attacker-controlled JavaScript code in a privileged context (such as the browser's internal code or extensions).
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
FirefoxWeb browser
< 100.0.2< 100.3.0
Firefox EsrWeb browser
< 91.9.1< 91.9.1CVSS 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 Firefox version (Stable/Beta)Open Firefox, go to Menu > Help > About Firefox. The version number is displayed in the window that opens.Affected if Version is less than 100.0.2 (for Stable) or 100.3.0 (for Beta) - note that Beta releases before 100.3.0 are also affected
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Check Firefox ESR versionOpen Firefox ESR, go to Menu > Help > About Firefox. The version number is displayed in the window that opens.Affected if Version is less than 91.9.1
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Check Thunderbird versionOpen Thunderbird, go to Menu > Help > About Thunderbird. The version number is displayed in the window that opens.Affected if Version is less than 91.9.1
If any installed Firefox (Stable, Beta, or ESR) or Thunderbird version falls below the respective patched version listed, the environment is affected by this vulnerability.
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 · scoped91.9.1100.0.2100.3.0
Update affected products to the patched versions: Firefox ESR to 91.9.1+, Firefox to 100.0.2+, Firefox for Android to 100.3.0+, and Thunderbird to 91.9.1+. Organizations should deploy these updates via their standard patch management processes.
Firefox 100.0.2+ (desktop) / 100.3.0+ (Android), Firefox ESR 91.9.1+, Thunderbird 91.9.1+
- Check current version of Firefox/Thunderbird by navigating to Help > About (or Settings > About in Thunderbird)
- Download Firefox 100.0.2 (desktop), Firefox 100.3.0 (Android), Firefox ESR 91.9.1, or Thunderbird 91.9.1 from the official Mozilla website
- Install the updated version of your product
- Restart the browser or email client to apply the update
- Verify the update was successful by checking the version again
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
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-2022-1802 — 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-2022-1802 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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- 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
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