Microsoft IIS allows remote attackers to obtain source code fragments using +.htr
| iis-htr-obtain-code (5104) |  Medium Risk |
Description:
Microsoft Internet Information Server (IIS) could allow a remote attacker to obtain source code fragments under restricted conditions, due to a variant of the "File Fragment Reading via .HTR" vulnerability. (For more information about the "File Fragment Reading via .HTR" vulnerability, see Microsoft Security Bulletin MS00-031. See References.) By sending a URL request with an appended +.htr, an attacker could be sent parts of the .ASP (Active Server Page) source code.
Platforms Affected:
- Microsoft, IIS 4.0
- Microsoft, IIS 5.0
- Microsoft, Personal Web Server 4.0
Remedy:
Apply the appropriate patch for your system, as listed in Microsoft Security Bulletin MS01-004, MS01-041, or MS02-001. See References.
Microsoft first addressed the "File Fragment Reading via .HTR" vulnerability in Microsoft Security Bulletin MS00-031. However, new variants of this vulnerability have resulted in the release of an additional Microsoft Security Bulletins and updated patches. The most current patch for this vulnerability is available in Microsoft Security Bulletin MS02-001.
For best security practices, if .HTR functionality is not required, disable the .HTR script mapping, as listed in Microsoft Security Bulletin MS01-004. See References.
For Windows NT 4.0:
Microsoft originally provided patches for this vulnerability in MS00-031, MS00-044, MS01-041, and MS02-001 but they were superseded by the patch released with MS02-018. See References.
For Windows 2000:
Apply the appropriate patch for your system, as listed in Microsoft Security Bulletin MS02-001. See References.
For IIS:
Microsoft originally provided a patch for this vulnerability in MS02-018, but it was superseded by the patch released with MS02-062, and then superseded by the patch released with MS03-018. See References.
Consequences:
Obtain Information
References:
- BugTraq Mailing List, Fri Aug 04 2000 - 10:39:00 CDT, More information on MS00-044 at http://archives.neohapsis.com/archives/bugtraq/2000-08/0018.html.
- ISBASE Security Advisory SA2000-02, IIS ISM.DLL truncation exposes file content at http://archives.neohapsis.com/archives/bugtraq/2000-07/0233.html.
- Macromedia/Allaire Security Bulletin ASB00-20, Patch Available for "Absent Directory Browser Argument" Vulnerability at http://online.securityfocus.com/advisories/2460.
- Microsoft Security Bulletin MS00-031, Patch Available for "Undelimited .HTR Request" and "File Fragment Reading via .HTR" Vulnerabilities at http://www.microsoft.com/technet/security/bulletin/ms00-031.mspx.
- Microsoft Security Bulletin MS00-044, Patch Available for 'Absent Directory Browser Argument' Vulnerability at http://www.microsoft.com/technet/security/bulletin/ms00-044.mspx.
- Microsoft Security Bulletin MS00-044 FAQ, Microsoft Security Bulletin (MS00-044): Frequently Asked Questions at http://www.microsoft.com/technet/security/bulletin/fq00-044.mspx.
- Microsoft Security Bulletin MS01-004, Patch Available for New Variant of 'File Fragment Reading via .HTR' Vulnerability at http://www.microsoft.com/technet/security/bulletin/ms01-004.mspx.
- Microsoft Security Bulletin MS01-041, Malformed RPC Request Can Cause Service Failure at http://www.microsoft.com/technet/security/bulletin/ms01-041.mspx.
- Microsoft Security Bulletin MS02-001, Trusting Domains Do Not Verify Domain Membership of SIDs in Authorization Data at http://www.microsoft.com/technet/security/bulletin/ms02-001.mspx.
- Microsoft Security Bulletin MS02-018, Cumulative Patch for Internet Information Services (Q319733) at http://www.microsoft.com/technet/security/bulletin/ms02-018.mspx.
- Microsoft Security Bulletin MS02-062, Cumulative Patch for Internet Information Service (Q327696) at http://www.microsoft.com/technet/security/Bulletin/MS02-062.mspx.
- Microsoft Security Bulletin MS03-018, Cumulative Patch for Internet Information Service (811114) at http://www.microsoft.com/technet/security/bulletin/ms03-018.mspx.
- BID-1488: Microsoft IIS 4.0/5.0 Source Fragment Disclosure Vulnerability
- CVE-2000-0630: IIS 4.0 and 5.0 allows remote attackers to obtain fragments of source code by appending a +.htr to the URL, a variant of the File Fragment Reading via .HTR vulnerability.
- US-CERT VU#28565: Microsoft Internet Information Server (IIS) discloses contents of files via crafted request containing +.htr
Reported:
Jul 14, 2000
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