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FirefoxWeb browser · Mozilla

CVE-2009-3981

HIGH · 9.3 CVSS v2.0 Published 2009-12-17
Fix available
A fix is available. Upgrade to after 3.0.15 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
Unspecified vulnerability in the browser engine in Mozilla Firefox before 3.0.16, SeaMonkey before 2.0.1, and Thunderbird allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown 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

A detailed technical summary for this CVE is being prepared.

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:<= 3.0.15= 0.1= 0.2= 0.3= 0.4= 0.5= 0.6= 0.6.1= 0.7= 0.7.1= 0.8= 0.9
SeamonkeyApplication
Affected:<= 2.0= 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= 1.0.9= 1.0.99
ThunderbirdApplication
Affected:all versions

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

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 a release after 3.0.15
Vendor patch www.mozilla.org →
Recommended fix High confidence

Firefox 3.0.16, SeaMonkey 2.0.1, and corresponding patched Thunderbird release

  1. Back up all user data, bookmarks, and passwords from the current installation
  2. Download Firefox 3.0.16 from the Mozilla archives or a trusted source
  3. Close all Firefox instances and running processes
  4. Install Firefox 3.0.16 over the existing installation
  5. For SeaMonkey users: Install SeaMonkey 2.0.1 over the existing installation
  6. For Thunderbird users: Upgrade Thunderbird to the corresponding patched version (refer to mfsa2009-65 for Thunderbird-specific fix)
  7. Restart the application and verify functionality
  8. Ensure any third-party extensions are compatible with the new version
Caveat Old browser versions from 2009-2010 may have compatibility issues with modern websites and web standards; some legacy extensions may not work

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

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,950. Get the upgrade done

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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-2009-3981 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