FirefoxWeb browser · Mozilla

CVE-2009-2463

HIGH · 10.0 CVSS v2.0 Published 2009-07-22
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
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
Multiple integer overflows in the (1) PL_Base64Decode and (2) PL_Base64Encode functions in nsprpub/lib/libc/src/base64.c in Mozilla Firefox before 3.0.12, Thunderbird before 2.0.0.24, and SeaMonkey before 1.1.19 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors that trigger buffer overflows.

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
How this class of weakness works · CWE-189

A legacy NVD category grouping numeric mistakes — overflows, truncation, sign errors — where a miscalculated value goes on to drive a dangerous decision such as a memory allocation or a bounds check. It is a bucket rather than one specific bug. Remediation is checked arithmetic and validating any computed size or index before it is used.

General guidance for the numeric errors class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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:= 0.1= 0.2= 0.3= 0.4= 0.5= 0.6= 0.6.1= 0.7= 0.7.1= 0.8= 0.9= 0.9.1
ThunderbirdApplication
Affected:= 2.0.0.0= 2.0.0.1= 2.0.0.2= 2.0.0.3= 2.0.0.4= 2.0.0.5= 2.0.0.6= 2.0.0.7= 2.0.0.8= 2.0.0.9= 2.0.0.11= 2.0.0.12

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
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/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
Patch available Apply the vendor patch
Recommended fix High confidence

Firefox 3.0.12+ or Thunderbird 2.0.0.24+ (or current supported major versions)

  1. Identify the currently installed Firefox or Thunderbird version
  2. For Firefox: Upgrade to version 3.0.12 or later (or migrate to a supported modern Firefox version)
  3. For Thunderbird: Upgrade to version 2.0.0.24 or later (or migrate to a supported modern Thunderbird version)
  4. Restart the application after upgrade
  5. Verify the new version is installed by checking About/Help > Version information
Caveat Firefox 3.0.x and Thunderbird 2.0.x are legacy versions; upgrading to current versions may require data migration and will change the user interface significantly. Ensure email data and bookmarks are backed up before upgrading.

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

We can apply and verify the patch for your build — typical engagement from $1,950. Get the patch applied

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2009-2463 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2009-2463 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