FirefoxWeb browser · Mozilla
CVE-2012-5837
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 · uneditedThe Web Developer Toolbar in Mozilla Firefox before 17.0 executes script with chrome privileges, which allows user-assisted remote attackers to conduct cross-site scripting (XSS) attacks via a crafted string.
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 confidenceThe Web Developer Toolbar extension in Mozilla Firefox versions prior to 17.0 contains a cross-site scripting vulnerability where it improperly executes scripts with chrome (privileged) privileges when processing a crafted string, allowing user-assisted remote attackers to inject and execute arbitrary JavaScript in the browser context.
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
<= 16.0.2= 0.1= 0.2= 0.3= 0.4= 0.5= 0.6= 0.6.1= 0.7= 0.7.1= 0.8= 0.9CVSS 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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Check Firefox versionOpen Firefox, click Help > About Mozilla Firefox, or run 'firefox --version' from command line. The version number displayed must be 16.0.2 or earlier.Affected if Firefox version is 16.0.2 or earlier (including older releases like 15.x, 14.x, etc.)
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Verify Web Developer Toolbar extension is installedOpen Firefox, go to Add-ons > Extensions, or navigate to about:addons. Look for an entry named 'Web Developer' in the list of installed extensions.Affected if The Web Developer Toolbar extension is present in the browser.
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Check Web Developer Toolbar versionIn about:addons under the Extensions section, click on the Web Developer extension to view its details. Note the version number shown (typically displayed as 0.x format).Affected if The extension version is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.6.1, 0.7, 0.7.1, 0.8, or 0.9.
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Confirm extension is enabledIn about:addons under Extensions, verify the Web Developer entry shows as 'Enabled' (not disabled or manually disabled).Affected if The Web Developer Toolbar extension is enabled in Firefox.
A user is affected if they have Firefox version 16.0.2 or earlier with the Web Developer Toolbar extension (versions 0.1 through 0.9) installed and enabled in their browser.
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 17.0 or later, which includes the patched Web Developer Toolbar, or disable/uninstall the vulnerable Web Developer Toolbar extension until a patched version is available.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 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 $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-5837 — 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-2012-5837 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