Q277873: Patch for "Web Server File Request Parsing" Vulnerability
Article: Q277873
Product(s): Internet Information Server
Version(s): 4.0,5.0
Operating System(s):
Keyword(s): kbSecurity kbWinNT400PreSP7Fix kbWin2000PreSP2Fix kbWin2000SP2Fix kbgraphxlinkcritical
Last Modified: 08-MAY-2002
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The information in this article applies to:
- Microsoft Internet Information Services version 5.0
- Microsoft Internet Information Server version 4.0
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SYMPTOMS
========
Microsoft has released a patch that eliminates a serious security vulnerability
in Microsoft Internet Information Services (IIS) 5.0 or Internet Information
Server 4.0. When IIS receives a valid request for an executable file, it passes
the name of the requested file to the underlying operating system for
processing. However, because of an implementation flaw, it is possible to create
a specially malformed file request that contains both a file name and one or
more operating system commands. When it receives such a request, IIS passes the
entire string to the operating system, which first processes the file, and then
executes the commands. The file must reside in a folder to which the user has
execute permissions, but it does not necessarily need to be an executable file.
The ability to execute operating system commands on a Web server can enable a
malicious user to take virtually any action that an interactively logged on user
can take. Although this does not give the malicious user administrative control
over the server, it can nevertheless allow him to cause widespread damage. He
could, for instance, add, delete or change files on the server, run code that
was already on the server, or upload and run the code of his choice.
For more information on this vulnerability, see the following Microsoft Web
site:
http://www.microsoft.com/technet/security/bulletin/ms00-086.asp
RESOLUTION
==========
Windows 2000
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To resolve this problem, obtain the latest service pack for Windows 2000. For
additional information, please see the following article in the Microsoft
Knowledge Base:
Q260910 How to Obtain the Latest Windows 2000 Service Pack
The following files are available for download from the Microsoft Download
Center:
US English:
DownloadDownload Q277873_W2K_SP2_x86_en.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25547)
Chinese (Simplified):
DownloadDownload Q277873_W2K_SP2_x86_cn.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25580)
Chinese (Traditional):
DownloadDownload Q277873_W2K_SP2_x86_tw.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25581)
For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:
Q119591 How to Obtain Microsoft Support Files from Online Services
Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. After it is posted, the file is housed on
secure servers that prevent any unauthorized changes to the file.
The English version of this fix should have the following file attributes or
later:
Date Time Version Size File name
------------------------------------------------------
11/27/2000 10:12p 5.0.2195.2785 122,640 Iisrtl.dll
11/27/2000 10:12p 5.0.2195.2784 357,136 W3svc.dll
Windows NT 4.0
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A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem.
To resolve this problem, contact Microsoft Product Support Services to obtain the
fix. For a complete list of Microsoft Product Support Services phone numbers and
information on support costs, please go to the following address on the World
Wide Web:
http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS
NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.
The following files are available for download from the Microsoft Download
Center:
NOTE: It is important that you have installed the latest service pack before you
apply this patch.
US English:
DownloadDownload Arbexei.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25964)
Chinese (Simplified):
DownloadDownload Arbexei.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25966)
Chinese (Traditional):
DownloadDownload Arbexei.exe now
(http://www.microsoft.com/downloads/release.asp?ReleaseID=25965)
For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:
Q119591 How to Obtain Microsoft Support Files from Online Services
Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. After it is posted, the file is housed on
secure servers that prevent any unauthorized changes to the file.
The English version of this fix should have the following file attributes or
later:
Date Time Version Size File name
----------------------------------------------------
11/08/2000 03:29p 4.2.753.1 214,544 adsiis.dll
11/09/2000 05:32p 4.2.753.1 330,672 asp.dll
11/08/2000 02:39p 11,396 httpext.h
11/09/2000 05:38p 4.2.753.1 55,904 httpodbc.dll
11/08/2000 03:29p 4.2.753.1 98,912 iischema.dll
11/08/2000 02:39p 28,851 iiscnfg.h
11/08/2000 03:27p 4.2.753.1 185,792 infocomm.dll
11/09/2000 05:38p 4.2.753.1 38,256 ssinc.dll
11/08/2000 03:28p 4.2.753.1 25,360 sspifilt.dll
11/09/2000 05:37p 4.2.753.1 229,008 w3svc.dll
NOTE: Due to file dependencies, this hotfix requires Microsoft Windows NT 4.0
Service Pack 5 or Service Pack 6a.
Microsoft Windows NT Server version 4.0, Terminal Server Edition
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To resolve this problem, obtain the Windows NT Server 4.0, Terminal Server
Edition, Security Rollup Package (SRP). For additional information about the
SRP, click the article number below to view the article in the Microsoft
Knowledge Base:
Q317636 Windows NT Server 4.0, Terminal Server Edition, Security Rollup
Package
STATUS
======
Windows 2000
------------
Microsoft has confirmed this to be a problem in Internet Information Services
5.0. This problem was first corrected in Windows 2000 Service Pack 2.
Windows NT 4.0
--------------
Microsoft has confirmed this to be a problem in Internet Information Server 4.0.
Additional query words: security_patch
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Keywords : kbSecurity kbWinNT400PreSP7Fix kbWin2000PreSP2Fix kbWin2000SP2Fix kbgraphxlinkcritical
Technology : kbiisSearch kbiis500 kbiis400
Version : :4.0,5.0
Hardware : x86
Issue type : kbbug
Solution Type : kbfix
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