Windows NtOperating system · Microsoft

CVE-2004-0900

HIGH · 10.0 CVSS v2.0 Published 2005-01-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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 DHCP Server service for Microsoft Windows NT 4.0 Server and Terminal Server Edition does not properly validate the length of certain messages, which allows remote attackers to execute arbitrary code via a malformed DHCP message, aka the "DHCP Request Vulnerability."

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

The DHCP Server service in Windows NT 4.0 Server and Terminal Server Edition fails to properly validate the length field in certain DHCP messages. This allows remote attackers to send malformed DHCP packets that can trigger a buffer overflow, leading to arbitrary code execution with SYSTEM privileges.

MitigationApply the relevant Microsoft patch if available (KB884020). For end-of-life Windows NT 4.0 systems, migrate to supported operating systems or implement strict network segmentation to isolate DHCP services and restrict unauthorized DHCP traffic at network boundaries.

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
Windows NtOperating system
Affected:= 4.0

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
Complete
Integrity
Complete
Availability
Complete

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

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 operating system version
    Run 'winmsd' or check System Properties to confirm the OS is Windows NT 4.0 Server or Windows NT 4.0 Terminal Server Edition. Use 'ver' command at command prompt which will show 'Windows NT Version 4.0'.
    Affected if The system is running any edition of Windows NT 4.0 (Server or Terminal Server Edition).
  2. Determine if the DHCP Server service is installed
    Open Control Panel, go to Services, or run 'net start' at command prompt to list all running services. Look for 'DHCP Server' or 'Microsoft DHCP Server' in the list.
    Affected if The DHCP Server service is installed and present in the services list.
  3. Check if the DHCP Server service is running
    Run 'net start' or check the Services control panel applet. Look for the DHCP Server service status - if it shows 'Started' or is running, the service is active.
    Affected if The DHCP Server service is currently running (even if not actively serving IPs at the moment).
  4. Verify DHCP server is listening on the network
    Run 'netstat -an' or use a network sniffer to check if UDP port 67 is listening. The command 'netstat -an | findstr :67' will show if port 67 is bound.
    Affected if The system is listening on UDP port 67, indicating the DHCP service is bound to the network interface.

You are affected if you are running Windows NT 4.0 Server or Terminal Server Edition with the DHCP Server service installed and running, as the buffer overflow vulnerability in the DHCP message length validation can be triggered by malformed DHCP packets sent to your network.

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

Apply the relevant Microsoft patch if available (KB884020). For end-of-life Windows NT 4.0 systems, migrate to supported operating systems or implement strict network segmentation to isolate DHCP services and restrict unauthorized DHCP traffic at network boundaries.

Fix this in Windows Nt Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing4.0 h
  • Review / QA2.0 h
30.0 hours of engineering $5,440
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Scan for this in your stack

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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-2004-0900 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