FirefoxWeb browser · Mozilla
CVE-2011-2669
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 · uneditedMozilla Firefox prior to 3.6 has a DoS vulnerability due to an issue in the validation of certificates.
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 · low confidenceMozilla Firefox versions prior to 3.6 contain a denial-of-service vulnerability stemming from improper certificate validation. The flaw allows remote attackers to cause the browser to crash or become unresponsive via specially crafted certificates.
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
< 3.6CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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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Confirm Mozilla Firefox is installedCheck for Firefox executable or application. On Windows, look for firefox.exe in Program Files or check Start menu. On macOS, check /Applications for Firefox.app. On Linux, run 'which firefox' or check /usr/bin/firefox.Affected if Firefox is not present on the system - this CVE does not apply.
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Determine installed Firefox version numberOpen Firefox, click Help > About Firefox (or navigate to about:support). Alternatively, run 'firefox --version' from command line on Linux. On Windows, right-click firefox.exe > Properties > Details for version information.Affected if No version can be determined - cannot assess vulnerability status.
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Compare version to affected rangeVerify the installed version against the affected range: versions prior to 3.6 are vulnerable. Common pre-3.6 versions include 3.0.x, 3.5.x series.Affected if Installed version is 3.5.x or earlier, or any version less than 3.6 - the environment is affected by this CVE.
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Verify certificate handling feature is in useThis vulnerability triggers when Firefox processes specially crafted certificates, typically during HTTPS connections or when importing certificate files.Affected if Browser is actively used for web browsing or handles SSL/TLS connections - the vulnerable code path can be reached.
If Mozilla Firefox version is less than 3.6 and the browser is used for web browsing or certificate handling, the environment is affected by CVE-2011-2669.
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.
From vendor data3.6
Upgrade Mozilla Firefox to version 3.6 or later; for modern environments, deploy current supported browser versions.
Fix this in Firefox
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 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 $1,456.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-2669 — 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-2011-2669 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