MessengerApplication · Yahoo

CVE-2004-0043

HIGH · 7.5 CVSS v2.0 Published 2004-02-03
Fix available
A fix is available. Upgrade to after 5.6.0.1351 or later.
See remediation →
84/100
Remediation priority · High
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
Buffer overflow in Yahoo Instant Messenger 5.6.0.1351 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long filename in the download feature.

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

Buffer overflow vulnerability in Yahoo Instant Messenger versions 5.6.0.1351 and earlier in the file download handling functionality. Attackers can trigger the vulnerability by sending or hosting a file with an excessively long filename, causing client crashes (DoS) and potentially enabling arbitrary code execution on the victim machine.

MitigationSince Yahoo Messenger has been discontinued, the primary mitigation is to migrate to a supported instant messaging platform. Alternatively, disable file transfer capabilities in Yahoo Messenger or implement endpoint detection and network filtering to block malicious file transfers.

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
MessengerApplication
Affected:<= 5.6.0.1351

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
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/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. Determine if Yahoo Messenger is installed
    Search for Yahoo Messenger installation directories (common paths include Program Files/Yahoo! or similar) or check system registry for Yahoo Messenger installation entries
    Affected if Yahoo Messenger is found installed on the system
  2. Identify the installed Yahoo Messenger version
    Access the About or Properties section within the Yahoo Messenger application, or right-click the executable and view version details if the program file ymsgr.exe exists
    Affected if The version number is 5.6.0.1351 or any version lower than this (e.g., 5.5, 5.0, earlier releases)
  3. Confirm file transfer functionality is enabled
    Open Yahoo Messenger settings and navigate to File Transfer preferences (typically found under Transfer or Preferences menus) to verify if the file transfer capability is turned on
    Affected if File transfers are enabled in the Yahoo Messenger configuration
  4. Review recent file transfer activity
    Check the Yahoo Messenger logs, transfer history folders, or Windows event logs for recent incoming or outgoing file transfers that may have involved excessively long filenames
    Affected if There is evidence of recent file transfer activity in the logs or transfer history

A user is affected if Yahoo Messenger version 5.6.0.1351 or earlier is installed AND file transfer functionality is enabled, as this combination allows the buffer overflow in file download handling to be triggered by a long filename.

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 5.6.0.1351
Interim mitigation

Since Yahoo Messenger has been discontinued, the primary mitigation is to migrate to a supported instant messaging platform. Alternatively, disable file transfer capabilities in Yahoo Messenger or implement endpoint detection and network filtering to block malicious file transfers.

Fix this in Messenger Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $910
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,456.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2004-0043 — 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-2004-0043 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