MessengerApplication · Yahoo

CVE-2005-1618

MEDIUM · 5.0 CVSS v2.0 Published 2005-05-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
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
The YMSGR URL handler in Yahoo! Messenger 5.x through 6.0 allows remote attackers to cause a denial of service (disconnect) via a room login or a room join request packet with a third : (colon) and an & (ampersand), which causes Messenger to send a corrupted packet to the server, which triggers a disconnect from the server.

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

Yahoo! Messenger versions 5.x through 6.0 contain a vulnerability in the YMSGR URL handler where specially crafted room login or room join request packets containing a third colon (:) and an ampersand (&) cause the client to send a malformed packet to the server, triggering an automatic server-side disconnect.

MitigationThis is a legacy client-side vulnerability in discontinued Yahoo! Messenger software. Organizations should ensure affected versions are not in use and consider migrating to supported enterprise communication platforms. No server-side remediation is possible.

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:= 5.5= 5.6= 6.0

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
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/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 executables in typical installation directories (Program Files\Yahoo!\, Program Files (x86)\Yahoo!\) or review installed programs via Windows Add or Remove Programs
    Affected if Yahoo Messenger executable files are present on the system
  2. Identify the installed Yahoo Messenger version
    Right-click the Yahoo Messenger executable, select Properties, and view the Version information tab, or check the version listed in Add or Remove Programs
    Affected if The installed version is 5.5, 5.6, or 6.0
  3. Verify the YMSGR URL handler is registered
    Check Windows Registry under HKEY_CLASSES_ROOT\YMSGR for protocol handler entries, or observe if clicking ymsgr: links opens Yahoo Messenger
    Affected if The YMSGR URL protocol handler is registered and functional

A system is affected if Yahoo Messenger version 5.5, 5.6, or 6.0 is installed and the YMSGR URL handler is active, as the vulnerability triggers when specially crafted room login or join request packets with a third colon and ampersand are processed.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

This is a legacy client-side vulnerability in discontinued Yahoo! Messenger software. Organizations should ensure affected versions are not in use and consider migrating to supported enterprise communication platforms. No server-side remediation is possible.

Fix this in Messenger Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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Scan for this in your stack

Free · runs locally
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-2005-1618 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