CVE-1999-0570
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 · uneditedWindows NT is not using a password filter utility, e.g. PASSFILT.DLL.
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 confidenceWindows NT is not utilizing a password filter utility such as PASSFILT.DLL, which is responsible for enforcing password complexity requirements during password changes. Without this filter, the system cannot validate that passwords meet minimum complexity standards, allowing weak or easily guessable passwords to be set.
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 dataall versionsCVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check if password filter is registered in the registryOpen Registry Editor and navigate to HKLM\SYSTEM\CurrentControlSet\Control\Lsa. Look for the 'Notification Packages' value and see if any password filter DLL (such as PASSFILT) is listed.Affected if The 'Notification Packages' value exists but does not contain any password filter DLL name, or the value does not exist at all.
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Verify PASSFILT.DLL exists in the system directoryCheck if PASSFILT.DLL exists in the Windows system directory (typically C:\WINDOWS\System32 or C:\WINNT\System32).Affected if PASSFILT.DLL does not exist in the system directory.
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Confirm password filter is actively loadedUse the registry to verify that a password filter DLL is actually listed in the 'Notification Packages' REG_MULTI_SZ value under HKLM\SYSTEM\CurrentControlSet\Control\Lsa.Affected if No password filter DLL name appears in the Notification Packages entry.
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Check for custom password filtersReview the 'Notification Packages' registry value to identify any registered password filter DLLs, whether Microsoft's PASSFILT or a custom third-party filter.Affected if The list is empty or does not contain any password filter DLL.
The system is affected if no password filter DLL (such as PASSFILT.DLL) is registered in the Windows registry Notification Packages configuration, allowing weak passwords to be set without complexity validation.
Generated from the published advisory. Verify against your own configuration.
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 · scopedImplement a password filter DLL (such as Microsoft's PASSFILT.DLL or a custom password filter) to enforce password complexity requirements and reject passwords that do not meet defined policy criteria.
Migrate to a supported Windows version (Windows 10/11 or Windows Server 2016+)
- Migrate away from Windows NT to a supported Windows version (e.g., Windows 10/11 or Windows Server 2019+) as Windows NT is end-of-life and no longer receives security updates.
- If immediate migration is not possible, implement a custom password filter DLL (such as PASSFILT.DLL) to enforce stronger password policies, though this is a workaround rather than a proper fix.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0570 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-1999-0570 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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