dbcve.org
Windows NtOperating system · Microsoft

CVE-1999-0227

MEDIUM · 5.0 CVSS v2.0 Published 1997-06-01
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
Access violation in LSASS.EXE (LSA/LSARPC) program in Windows NT allows a denial of service.

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

Access violation in LSASS.EXE (Local Security Authority Subsystem) on Windows NT allows remote or local attackers to cause a denial of service by triggering an unhandled exception in the LSA/LSARPC service, crashing the security subsystem.

MitigationWindows NT is obsolete and no longer supported; migrate affected systems to a supported Windows version. If running legacy NT systems is unavoidable, restrict network access to LSARPC endpoints and apply any historical Microsoft patches.

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
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. Identify the operating system version
    Run 'winmsd' or check System Properties to confirm the Windows version. On command line: 'ver' or 'systeminfo | findstr /C:"Windows NT"'
    Affected if The system is running Windows NT version 4.0 exactly (not later Windows versions)
  2. Verify the LSASS.EXE process is present
    Open Task Manager or run 'tasklist /FI "IMAGENAME eq lsass.exe"' to confirm the Local Security Authority Subsystem process is running
    Affected if LSASS.EXE is running, which is the default state on Windows NT 4.0 systems
  3. Determine network exposure of LSARPC service
    Check if the LSARPC endpoint (TCP/UDP port 445 or named pipe \pipe\lsarpc) is accessible from network sources. Use 'netstat -an' to list listening ports and assess network accessibility
    Affected if The LSARPC service is exposed to untrusted network segments or the system is directly internet-facing on these endpoints

A system is affected if it is running Windows NT 4.0 with LSASS.EXE active and the LSARPC service is network-accessible to potential attackers.

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

Windows NT is obsolete and no longer supported; migrate affected systems to a supported Windows version. If running legacy NT systems is unavoidable, restrict network access to LSARPC endpoints and apply any historical Microsoft patches.

Fix this in Windows Nt Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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Scan for this in your stack

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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-1999-0227 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