CVE-2002-0072
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 · uneditedThe w3svc.dll ISAPI filter in Front Page Server Extensions and ASP.NET for Internet Information Server (IIS) 4.0, 5.0, and 5.1 does not properly handle the error condition when a long URL is provided, which allows remote attackers to cause a denial of service (crash) when the URL parser accesses a null pointer.
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 · moderate confidenceThe w3svc.dll ISAPI filter in Front Page Server Extensions and ASP.NET for IIS 4.0, 5.0, and 5.1 contains a null pointer dereference vulnerability. When an overly long URL is submitted, the URL parser enters an error condition but fails to handle it properly, leading to a null pointer access and service crash.
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= 4.0= 5.0CVSS 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 checksWork through these to decide whether this CVE applies to you.
-
Confirm IIS is installed and identify versionOpen IIS Manager (inetmgr) and check the About information, or run 'iisreset /status' and check version info in registry at HKLM\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters\MajorVersionAffected if The version shown is 4.0 (IIS 4.0) or 5.0 (IIS 5.0)
-
Check for Front Page Server ExtensionsLook for the presence of fpexedll.dll or fpmmc.dll in the IIS scripts folder (typically C:\WINNT\system32\inetsrv\) or check the IIS metabase for the FrontPage virtual server configurationAffected if Front Page Server Extensions are installed on the IIS server
-
Check for ASP.NET ISAPI filter registrationOpen IIS Manager, right-click the web server, select Properties, and view the ISAPI Filters tab - look for aspnet_filter.dll entryAffected if The ASP.NET ISAPI filter (aspnet_filter.dll) is registered and enabled
-
Verify w3svc.dll is in useCheck the IIS metabase (MetaEdit tool or adsutil.vbs) for the W3SVC service definition, or look for w3svc.dll in the system32 directory (typically C:\WINNT\system32\w3svc.dll)Affected if w3svc.dll exists and is loaded by the IIS worker process
The environment is affected if IIS version 4.0 or 5.0 is running with Front Page Server Extensions and/or ASP.NET ISAPI filters enabled, as the vulnerable w3svc.dll URL parser handles these extensions.
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.
From vendor dataApply the relevant Microsoft security patch from 2002, or migrate away from these legacy IIS versions (4.0/5.0/5.1) which are all end-of-life and no longer supported.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 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 $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2002-0072 — 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-2002-0072 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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