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FirefoxWeb browser · Mozilla

CVE-2012-3974

MEDIUM · 6.9 CVSS v2.0 Published 2012-08-29
Fix available
A fix is available. Upgrade to after 14.0 or later.
See remediation →
74/100
Remediation priority · Elevated
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
Untrusted search path vulnerability in the installer in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, and Thunderbird ESR 10.x before 10.0.7 on Windows allows local users to gain privileges via a Trojan horse executable file in a root directory.

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

Untrusted search path vulnerability in Mozilla Firefox and Thunderbird installers on Windows allows local privilege escalation via a Trojan horse executable placed in the root directory, exploiting the installer's insecure executable search order.

MitigationUpdate to Firefox 15.0+, Firefox ESR 10.0.7+, Thunderbird 15.0+, or Thunderbird ESR 10.0.7+ to patch the installer vulnerability.

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:<= 14.0= 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= 1.4.1= 1.5
ThunderbirdApplication
Affected:<= 14.0= 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
Thunderbird EsrApplication
Affected:= 10.0= 10.0.1= 10.0.2= 10.0.3= 10.0.4= 10.0.5= 10.0.6

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
Local
Complexity
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/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 installed Firefox version on Windows
    Open Firefox, go to Help > About Firefox, or run 'firefox -v' from command prompt. Alternatively, check the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox\CurrentVersion or in 64-bit Windows HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Mozilla Firefox\CurrentVersion
    Affected if The version is 14.0 or lower, or matches 1.0.x, 1.4.1, or 1.5
  2. Check installed Thunderbird version on Windows
    Open Thunderbird, go to Help > About Thunderbird, or run 'thunderbird -v' from command prompt. Alternatively, check the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Thunderbird\CurrentVersion or in 64-bit Windows HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Thunderbird\CurrentVersion
    Affected if The version is 14.0 or lower, or matches 1.0.x, 1.5, 1.5.0.1, or ESR 10.0 through 10.0.6
  3. Verify the operating system is Windows
    Run 'systeminfo' or check system properties. This vulnerability only affects Windows installers.
    Affected if The operating system is Windows and the installed product version is in the affected list
  4. Check for suspicious executables in installer directories
    Examine directories where Firefox or Thunderbird installers were downloaded or run. Look for unexpected .exe files with common names (such as dllhost.exe, rundll32.exe, cmd.exe) that were created around the time of installation.
    Affected if Unexpected executables exist in directories where the installer was run, suggesting potential exploitation attempt
  5. Review installation source location
    Check the download location and extraction directory for the installer. Determine if it was run from a directory writable by other users (such as shared folders, temp directories, or network drives).
    Affected if The installer was run from a directory with broader write permissions where another local user could have placed a malicious executable

A user is affected if they are running Firefox 14.0 or earlier, Thunderbird 14.0 or earlier, or Thunderbird ESR 10.0-10.0.6 on Windows and their installer was run from a directory where an attacker could have placed a malicious executable.

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 14.0
Interim mitigation

Update to Firefox 15.0+, Firefox ESR 10.0.7+, Thunderbird 15.0+, or Thunderbird ESR 10.0.7+ to patch the installer vulnerability.

Fix this in Firefox Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

Scan for this in your stack

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dbcve dependency scanner

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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-2012-3974 in production — separate from our analysis above.

No notes yet

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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