dbcve.org
Internet Information ServicesApplication · Microsoft

CVE-2007-2815

HIGH · 10.0 CVSS v2.0 Published 2007-05-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
High EPSS 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
The "hit-highlighting" functionality in webhits.dll in Microsoft Internet Information Services (IIS) Web Server 5.0 only uses Windows NT ACL configuration, which allows remote attackers to bypass NTLM and basic authentication mechanisms and access private web directories via the CiWebhitsfile parameter to null.htw.

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's hit-highlighting feature (webhits.dll) contains an authentication bypass vulnerability where the CiWebhitsfile parameter to null.htw only validates access using Windows NT file system ACLs instead of enforcing IIS-configured NTLM or basic authentication, allowing unauthorized remote access to protected web directories.

MitigationDisable the webhits.dll ISAPI extension in IIS 5.0 or migrate to a supported IIS version that properly enforces authentication mechanisms for hit-highlighting functionality.

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Verify IIS version is 5.0
    Check the IIS version by running 'iisreset /status' or checking the Windows version (IIS 5.0 shipped with Windows 2000 Server). Open IIS Manager, right-click the server, and select Properties to confirm the version number.
    Affected if The server is running Microsoft Internet Information Services version 5.0 specifically.
  2. Confirm webhits.dll ISAPI extension is registered
    Open IIS Manager, navigate to the Web Service Extensions node. Check if 'Hit Highlighting' or 'webhits.dll' is listed as an allowed extension.
    Affected if The webhits.dll ISAPI extension is registered and set to Allowed or Prohibited status in IIS.
  3. Check for .htw script mapping
    In IIS Manager, go to the website properties, then Home Directory > Configuration > Mappings. Look for a .htw extension mapped to webhits.dll.
    Affected if A .htw extension mapping to webhits.dll exists in the IIS script mappings.
  4. Test authentication bypass via null.htw
    Attempt to access a protected resource using the URL pattern: /null.htw?CiWebhitsfile=../../../../win.ini. If the file contents are returned without authentication prompt, the vulnerability is present.
    Affected if The server returns file contents (such as win.ini) via the null.htw with CiWebhitsfile parameter without requiring authentication.

The environment is affected if running IIS 5.0 with webhits.dll ISAPI extension enabled and the .htw script mapping is active, allowing unauthenticated access to protected files via the CiWebhitsfile parameter on null.htw.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable the webhits.dll ISAPI extension in IIS 5.0 or migrate to a supported IIS version that properly enforces authentication mechanisms for hit-highlighting functionality.

Recommended fix Moderate confidence

IIS 6.0 or later (Windows Server 2003+)

  1. 1. Verify the current IIS version by running 'inetmgr' or checking the Windows version (IIS 5.0 shipped with Windows 2000 Server)
  2. 2. Upgrade to a supported IIS version (IIS 6.0 or higher on Windows Server 2003/2008 or later)
  3. 3. After upgrade, verify the webhits.dll and .htw handler mappings are not present or are properly secured
  4. 4. Test that authentication mechanisms (NTLM, Basic Auth) are functioning correctly on the new IIS version
  5. 5. Review and apply any available security patches for the new IIS version
Caveat Upgrading from IIS 5.0 to IIS 6.0/7.0 requires Windows Server upgrade; IIS 6.0 introduced significant architectural changes including new worker process isolation mode that may require application compatibility testing

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Internet Information Services Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2007-2815 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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