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SeamonkeyApplication · Mozilla

CVE-2006-2781

MEDIUM · 6.4 CVSS v2.0 Published 2006-06-02
Fix available
A fix is available. Upgrade to after 1.5.0.3 or later.
See remediation →
73/100
Remediation priority · Elevated
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
Double free vulnerability in nsVCard.cpp in Mozilla Thunderbird before 1.5.0.4 and SeaMonkey before 1.0.2 allows remote attackers to cause a denial of service (hang) and possibly execute arbitrary code via a VCard that contains invalid base64 characters.

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

Double-free vulnerability in nsVCard.cpp in Mozilla Thunderbird and SeaMonkey. When parsing a VCard containing invalid base64 characters, the code incorrectly frees the same memory pointer twice, leading to heap corruption that can cause denial of service (application hang) or potentially allow arbitrary code execution.

MitigationUpgrade Thunderbird to version 1.5.0.4 or later, and SeaMonkey to version 1.0.2 or later, which contain the corrected memory management logic in the VCard parsing routine.

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
SeamonkeyApplication
Affected:<= 1.0.1
ThunderbirdApplication
Affected:<= 1.5.0.3

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
None
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:P/A:P

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 email client product
    Check if Mozilla Thunderbird or SeaMonkey is installed. On Windows check Add/Remove Programs or the application's Help > About. On Linux check package manager listings (dpkg -l, rpm -qa) or locate the executable path.
    Affected if The product is Mozilla Thunderbird or SeaMonkey
  2. Determine the installed version of Thunderbird
    In Thunderbird, go to Help > About Mozilla Thunderbird and note the exact version number displayed (for example, 1.5.0.3, 1.5.0.2, etc.).
    Affected if The version is 1.5.0.3 or earlier
  3. Determine the installed version of SeaMonkey
    In SeaMonkey, go to Help > About SeaMonkey and note the exact version number displayed (for example, 1.0.1, 1.0.0, etc.).
    Affected if The version is 1.0.1 or earlier

A system is affected if it runs Thunderbird version 1.5.0.3 or earlier, or SeaMonkey version 1.0.1 or earlier, and processes VCard attachments containing invalid base64 characters.

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 1.5.0.3
Interim mitigation

Upgrade Thunderbird to version 1.5.0.4 or later, and SeaMonkey to version 1.0.2 or later, which contain the corrected memory management logic in the VCard parsing routine.

Fix this in Seamonkey Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

Free · runs locally
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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-2006-2781 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