dbcve.org
FirefoxWeb browser · Mozilla

CVE-2011-2373

HIGH · 7.6 CVSS v2.0 Published 2011-06-30
Fix available
A fix is available. Upgrade to after 3.6.17 or later.
See remediation →
85/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 vulnerability in Mozilla Firefox before 3.6.18 and 4.x through 4.0.1, Thunderbird before 3.1.11, and SeaMonkey through 2.0.14, when JavaScript is disabled, allows remote attackers to execute arbitrary code via a crafted XUL document.

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

Use-after-free vulnerability in Mozilla products (Firefox, Thunderbird, SeaMonkey) when JavaScript is disabled. Attackers can exploit this by crafting a malicious XUL document that triggers a use-after-free condition in memory, potentially allowing arbitrary code execution.

MitigationUpgrade to Firefox 3.6.18+/4.0.2+, Thunderbird 3.1.11+, or SeaMonkey 2.0.14+. Additionally, ensuring JavaScript is enabled (the default setting) prevents exploitation since this vulnerability only triggers when JavaScript is disabled.

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
Affected:<= 3.6.17= 1.0= 1.0.1= 1.0.2= 1.0.3= 1.0.4= 1.0.5= 1.0.6= 1.0.7= 1.0.8= 1.5= 1.5.0.1
SeamonkeyApplication
Affected:= 1.0= 1.0.1= 1.0.2= 1.0.3= 1.0.4= 1.0.5= 1.0.6= 1.0.7= 1.0.8= 1.0.9= 1.1= 1.1.1
ThunderbirdApplication
Affected:<= 3.1.10= 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

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
Network
Complexity
High
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:H/Au:N/C:C/I:C/A:C

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. Identify the installed Mozilla product
    Open the application and go to Help > About (Firefox/Thunderbird) or Help > About SeaMonkey. Alternatively, check the application's executable or installation directory for version information.
    Affected if The product is Firefox, Thunderbird, or SeaMonkey
  2. Determine the installed version
    Note the exact version number displayed in the About dialog. For Windows, also check the file properties of the main executable (firefox.exe, thunderbird.exe, seamonkey.exe).
    Affected if The version matches one listed in the affected ranges: Firefox <= 3.6.17 or 1.0-1.0.8 or 1.5/1.5.0.1; SeaMonkey 1.0-1.1.1; Thunderbird <= 3.1.10 or 0.1-0.8
  3. Check if JavaScript is disabled
    In Firefox: Tools > Options > Content (uncheck 'Enable JavaScript'). In Thunderbird: Tools > Options > Security (uncheck 'Enable JavaScript'). In SeaMonkey: Edit > Preferences > Advanced (uncheck 'Enable JavaScript'). Alternatively, check the user.js or prefs.js configuration file for 'javascript.enabled' set to false.
    Affected if JavaScript is disabled (javascript.enabled = false in config) AND the version is in the affected list
  4. Inspect browser configuration files
    Locate the prefs.js file in the profile directory (typically in %APPDATA%\Mozilla\Firefox\Profiles\ on Windows, ~/.mozilla/firefox/ on Linux, ~/Library/Application Support/Firefox/Profiles/ on macOS). Search for the string 'javascript.enabled' and note its value.
    Affected if pref file contains 'user_pref("javascript.enabled", false);' and version is affected

A user is affected only if they are running a vulnerable version of Firefox, Thunderbird, or SeaMonkey AND JavaScript has been manually disabled from its default enabled state.

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 a release after 3.6.17
Interim mitigation

Upgrade to Firefox 3.6.18+/4.0.2+, Thunderbird 3.1.11+, or SeaMonkey 2.0.14+. Additionally, ensuring JavaScript is enabled (the default setting) prevents exploitation since this vulnerability only triggers when JavaScript is disabled.

Fix this in Firefox Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2011-2373 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2011-2373 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