dbcve.org
FirefoxWeb browser · Mozilla

CVE-2012-4182

HIGH · 9.3 CVSS v2.0 Published 2012-10-10
Fix available
A fix is available. Upgrade to 10.0.8 / 16.0 or later.
See remediation →
100/100
Remediation priority · Urgent
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 the nsTextEditRules::WillInsert function in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8, and SeaMonkey before 2.13 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.

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's nsTextEditRules::WillInsert function in the editor component allows remote attackers to execute arbitrary code or cause heap memory corruption via unspecified vectors involving crafted web content.

MitigationUpgrade to Firefox 16.0+, Firefox ESR 10.0.8+, Thunderbird 16.0+, Thunderbird ESR 10.0.8+, or SeaMonkey 2.13+ to patch the memory corruption flaw.

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:< 10.0.8< 16.0
Ubuntu LinuxOperating system
Affected:= 10.04= 11.04= 11.10= 12.04
Enterprise Linux DesktopOperating system
Affected:= 5.0= 6.0
Enterprise Linux EusOperating system
Affected:= 6.3
Enterprise Linux ServerOperating system
Affected:= 5.0= 6.0
Enterprise Linux WorkstationOperating system
Affected:= 5.0= 6.0
Debian LinuxOperating system
Affected:= 6.0
Thunderbird EsrApplication
Affected:< 10.0.8

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
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:M/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. Check Firefox version on Linux
    Run: firefox --version or dpkg -l | grep firefox or rpm -qa | grep firefox
    Affected if Version is below 10.0.8 (ESR) or below 16.0 (regular release)
  2. Check Firefox version via UI
    Open Firefox and navigate to Help > About Firefox
    Affected if Version displayed is below 10.0.8 or below 16.0
  3. Check Thunderbird version on Linux
    Run: thunderbird --version or dpkg -l | grep thunderbird or rpm -qa | grep thunderbird
    Affected if Version is below 10.0.8 (ESR)
  4. Check Thunderbird version via UI
    Open Thunderbird and navigate to Help > About Thunderbird
    Affected if Version displayed is below 10.0.8
  5. Check installed Mozilla packages via Ubuntu/Debian package manager
    Run: dpkg --list | grep -E 'firefox|thunderbird'
    Affected if Package version listed is below 10.0.8 or 16.0
  6. Check installed Mozilla packages via RHEL package manager
    Run: rpm -qa | grep -E 'firefox|thunderbird'
    Affected if Package version listed is below 10.0.8 or 16.0

If Firefox is below 10.0.8 (ESR) or below 16.0, or Thunderbird ESR is below 10.0.8, the system is vulnerable to this use-after-free flaw in the editor component.

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.

dbcve · scoped
Upgrade available Upgrade to 10.0.8 / 16.0 or later
Fixed in 10.0.816.0
Interim mitigation

Upgrade to Firefox 16.0+, Firefox ESR 10.0.8+, Thunderbird 16.0+, Thunderbird ESR 10.0.8+, or SeaMonkey 2.13+ to patch the memory corruption flaw.

Recommended fix High confidence

Firefox 16.0+ (or Firefox ESR 10.0.8+); Thunderbird 16.0+ (or Thunderbird ESR 10.0.8+); SeaMonkey 2.13+

  1. Identify the affected Mozilla product installed (Firefox, Thunderbird, or SeaMonkey) and its current version
  2. For Firefox ESR 10.x users: Upgrade to Firefox ESR 10.0.8 or later, or migrate to a supported ESR branch (e.g., ESR 17.x, ESR 24.x)
  3. For Firefox (non-ESR) users: Upgrade to Firefox 16.0 or later (recommended: latest stable version)
  4. For Thunderbird ESR 10.x users: Upgrade to Thunderbird ESR 10.0.8 or later, or migrate to a supported ESR branch
  5. For Thunderbird (non-ESR) users: Upgrade to Thunderbird 16.0 or later (recommended: latest stable version)
  6. For SeaMonkey users: Upgrade to SeaMonkey 2.13 or later
  7. On Linux systems (Ubuntu, Debian, Enterprise Linux): Use the system's package manager to update (e.g., apt-get update && apt-get upgrade for Debian/Ubuntu, yum update for RHEL/CentOS)
  8. Restart the application after upgrading
Caveat Upgrading to newer major versions may introduce UI changes or require reconfiguration; ensure compatibility with any dependent extensions or enterprise policies before deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firefox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2012-4182 — 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-2012-4182 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