Internet Information ServicesApplication · Microsoft

CVE-2001-0507

HIGH · 7.2 CVSS v2.0 Published 2001-09-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
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
IIS 5.0 uses relative paths to find system files that will run in-process, which allows local users to gain privileges via a Trojan horse file, aka the "System file listing privilege elevation" 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

IIS 5.0 on Windows 2000 uses relative path resolution to locate DLLs and executables that run in-process. A local user with file-system write access can place a malicious DLL/executable with the same name as a legitimate system file in a directory within IIS's search path. When IIS loads this Trojan horse file, it executes with SYSTEM-level privileges, achieving local privilege escalation.

MitigationApply Microsoft security patches from 2001 that address this vulnerability, or migrate away from IIS 5.0/Windows 2000 to a supported platform.

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
Internet Information ServicesApplication
Affected:= 5.0

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
Local
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/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. Confirm IIS 5.0 is installed
    Check the Windows version (must be Windows 2000) and verify IIS version by opening IIS Manager (inetmgr) or running 'iisreset /?' or checking HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InetStp in the registry for Version = 5.0
    Affected if System is Windows 2000 with IIS 5.0 installed and running
  2. Identify IIS search path directories
    Examine the system PATH environment variable and the IIS metabase for executable directories. Check directories under Inetpub (wwwroot, scripts, etc.) and system32
    Affected if Directories in IIS's executable search path are writable by non-privileged users
  3. Check for unauthorized DLLs/executables in IIS paths
    Scan directories in IIS's search path (especially Inetpub folders and system32) for files with names matching common system DLLs (such as wsasrv.dll, w3svc.dll, asp.dll) that were created or modified recently and are not part of a legitimate IIS installation
    Affected if Unexpected DLL or executable files exist in IIS search path directories with names matching system files
  4. Verify file system permissions on IIS directories
    Use icacls or NTFS permissions to check if standard users or low-privilege accounts have Write or Modify permissions to Inetpub directories, scripts folder, or other directories in IIS search path
    Affected if Non-privileged users have Write access to any directory IIS uses to locate DLLs/executables
  5. Review running IIS worker processes
    Check for IIS in-process applications (running under inetinfo.exe or dllhost.exe) and examine loaded DLLs using process monitoring tools. Look for DLLs loaded from user-writable directories
    Affected if IIS is running in-process applications and loading DLLs from directories writable by local users

Environment is affected if running unpatched IIS 5.0 on Windows 2000 where low-privilege users have write access to any directory in IIS's DLL/executable search path.

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 Microsoft security patches from 2001 that address this vulnerability, or migrate away from IIS 5.0/Windows 2000 to a supported platform.

Fix this in Internet Information Services Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2001-0507 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2001-0507 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
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