FirefoxWeb browser · Mozilla
CVE-2011-3666
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 before 3.6.25 and Thunderbird before 3.1.17 on Mac OS X do not consider .jar files to be executable files, which allows user-assisted remote attackers to bypass intended access restrictions via a crafted file. NOTE: this vulnerability exists because of an incorrect fix for CVE-2011-2372 on Mac OS X.
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 confidenceFirefox and Thunderbird on Mac OS X prior to versions 3.6.25 and 3.1.17 respectively fail to treat .jar (Java Archive) files as executable files, allowing security restrictions to be bypassed. This stems from an incorrect fix for CVE-2011-2372. The vulnerability is user-assisted, requiring the victim to interact with a crafted file.
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
<= 3.6.24= 0.1= 0.2= 0.3= 0.4= 0.5= 0.6= 0.6.1= 0.7= 0.7.1= 0.8= 0.9<= 3.1.16= 0.1= 0.2= 0.3= 0.4= 0.5= 0.6= 0.7= 0.7.1= 0.7.2= 0.7.3= 0.8CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
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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Identify installed Mozilla productOpen terminal and run: ps -ax | grep -iE 'firefox|thunderbird' or check /Applications folder for Firefox or ThunderbirdAffected if Neither Firefox nor Thunderbird is installed (not affected)
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Determine Firefox versionFor Firefox: click Firefox menu > About Firefox, or run: /Applications/Firefox.app/Contents/MacOS/firefox -versionAffected if Version is 3.6.24 or earlier, or one of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.6.1, 0.7, 0.7.1, 0.8, 0.9 (affected)
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Determine Thunderbird versionFor Thunderbird: click Thunderbird menu > About Thunderbird, or run: /Applications/Thunderbird.app/Contents/MacOS/thunderbird -versionAffected if Version is 3.1.16 or earlier, or one of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.7.1, 0.7.2, 0.7.3, 0.8 (affected)
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Confirm Mac OS X environmentRun: uname -a or click Apple menu > About This MacAffected if Operating system is not Mac OS X (not affected)
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Check if Java plugin is presentIn Firefox: go to Add-ons > Plugins; in Thunderbird: go to Tools > Add-ons > Plugins; look for Java plugin entryAffected if Java plugin is disabled or not installed (the JAR bypass does not apply, though the code flaw may still exist)
User is affected if they have Firefox <= 3.6.24 (or older version 0.1-0.9) or Thunderbird <= 3.1.16 (or older version 0.1-0.8) running on Mac OS X, with Java plugin enabled, and they can be tricked into interacting with a crafted .jar file.
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 dataUpgrade Firefox to version 3.6.25 or later and Thunderbird to version 3.1.17 or later on Mac OS X systems. Alternatively, disable Java plugin execution in the browser as a defense-in-depth measure.
Fix this in Firefox
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-3666 — 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-2011-3666 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
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