dbcve.org
Windows 2000Operating system · Microsoft

CVE-2000-1218

CRITICAL · 9.8 CVSS v3.1 Published 2000-04-14
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 default configuration for the domain name resolver for Microsoft Windows 98, NT 4.0, 2000, and XP sets the QueryIpMatching parameter to 0, which causes Windows to accept DNS updates from hosts that it did not query, which allows remote attackers to poison the DNS cache.

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 Windows DNS resolver default configuration sets QueryIpMatching to 0, causing it to accept DNS updates from any source rather than validating that the responder matches the original queried host, enabling remote attackers to poison the DNS cache.

MitigationSet the QueryIpMatching registry value to 1 to require IP address matching on DNS responses; however, these are end-of-life operating systems (Windows 98, NT 4.0, 2000, XP) that should be retired and replaced with supported versions.

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 2000Operating system
Affected:all versions
Windows 98Operating system
Affected:all versions
Windows 98seOperating system
Affected:all versions
Windows NtOperating system
Affected:= 4.0
Windows XpOperating system
Affected:all versions

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
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 Windows version
    Run 'winmsd' or check System Properties to determine the exact Windows version. Affected systems are Windows 98, 98se, NT 4.0, 2000, and XP.
    Affected if The system is running Windows 98, 98se, NT 4.0, 2000, or XP.
  2. Locate the DNS resolver registry key
    Navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Dnscache\Parameters in the Windows Registry Editor (regedit.exe).
    Affected if The registry path exists (Windows 2000/XP) or the system uses the default DNS resolver (Windows 98/NT).
  3. Check the QueryIpMatching value
    Inspect the QueryIpMatching value (REG_DWORD) under the DNS cache Parameters key. If the value does not exist, the default is 0.
    Affected if QueryIpMatching is set to 0 or is absent (default behavior accepts any DNS response without IP validation).
  4. Verify DNS client is enabled
    Confirm the DNS Client service (Dnscache) is running. Check Services.msc or run 'net start' to list running services.
    Affected if The DNS Client service is enabled and running, making the system use the vulnerable resolver logic.

A system is affected if it runs Windows 98, 98se, NT 4.0, 2000, or XP AND has QueryIpMatching set to 0 (or unset, defaulting to 0) in the DNS resolver configuration, allowing DNS cache poisoning.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Set the QueryIpMatching registry value to 1 to require IP address matching on DNS responses; however, these are end-of-life operating systems (Windows 98, NT 4.0, 2000, XP) that should be retired and replaced with supported versions.

Recommended fix High confidence
  1. These operating systems (Windows 98, 98se, NT 4.0, 2000, XP) are all end-of-life and no longer receive security updates from Microsoft.
  2. There is no vendor patch available for this vulnerability on these legacy systems.
  3. If applicable, migrate to a supported Windows version (Windows 10 or Windows 11) which does not have this vulnerability.
  4. As a configuration mitigation on modern systems (if applicable), ensure QueryIpMatching is set to 1 in the DNS resolver settings.
  5. For legacy systems that cannot be migrated, consider network-level mitigations such as blocking external DNS updates or using secure DNS (DNSSEC) on the network.
Caveat These legacy operating systems cannot be upgraded; complete system replacement is required

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

Fix this in Windows 2000 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2000-1218 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