CVE-1999-0154
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 · uneditedIIS 2.0 and 3.0 allows remote attackers to read the source code for ASP pages by appending a . (dot) to the end of the URL.
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 confidenceIIS versions 2.0 and 3.0 contain a vulnerability where appending a trailing dot (.) to a URL requesting an ASP page causes the server to return the page's source code instead of executing it. This is a classic source code disclosure issue stemming from improper URL handling in these legacy IIS 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= 3.0= 2.0CVSS 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
- Partial
- Integrity
- None
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:N/A:N
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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Identify IIS versionOpen a command prompt and run: iisreset /status or check the Windows registry at HKLM\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters\MajorVersionAffected if The version reported is 2.0 or 3.0 exactly
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Confirm ASP support is enabledCheck for the presence of ASP.dll in the system32 directory (typically C:\WINDOWS\system32\inetsrv\asp.dll) or check IIS Manager for ASP scripting engineAffected if ASP is installed and enabled on the server
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Test for source code disclosureUsing a web browser or curl tool, request any existing ASP page on the server with a trailing dot appended (e.g., http://target/page.asp.)Affected if The server returns unexecuted ASP source code (visible script tags, Response.Write statements, etc.) instead of processed HTML output
The server is vulnerable if it is running IIS 2.0 or 3.0, has ASP enabled, and returns source code when requesting an ASP page with a trailing dot.
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 dataIf these legacy IIS versions are still in production, migrate to a supported IIS version immediately. For historical systems that cannot be upgraded, implement URL filtering at a perimeter firewall or WAF to block requests containing trailing dots to ASP pages.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-1999-0154 — 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-1999-0154 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
- No spam, self-promotion, credentials, or personal data