Q249599: Virtual Directory Mapped to UNC Returns Server-Side Script Code
Article: Q249599
Product(s): Internet Information Server
Version(s): 4.0,5.0
Operating System(s):
Keyword(s): kbSecurity kbWin2000PreSP1Fix kbWinNT400PreSP7Fix kbgraphxlinkcritical
Last Modified: 30-APR-2002
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Internet Information Server version 4.0
- Microsoft Internet Information Services version 5.0
-------------------------------------------------------------------------------
SYMPTOMS
========
If a virtual directory on an Internet Information Server (IIS) computer is
mapped to a Universal Naming Convention (UNC) share, and a request for a file in
the directory contains one of several particular characters at the end of the
request, the expected Internet Server Application Programming Interface (ISAPI)
extension processing may not occur. This can result in the source code of the
file being sent to the browser.
CAUSE
=====
This problem can be caused by the use of a varying combination of special
characters at the end of the clients request.
RESOLUTION
==========
Windows 2000
------------
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
This fix is also available individually. The following files are available for
download from the Microsoft Download Center:
US English
DownloadDownload Q249599_W2K_SP1_X86_EN.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19982)
Arabic
DownloadDownload Q249599_W2K_SP1_X86_AR.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19983)
Chinese (Simplified)
DownloadDownload Q249599_W2K_SP1_X86_CN.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19985)
Chinese (Traditional)
DownloadDownload Q249599_W2K_SP1_X86_TW.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19995)
Dutch
DownloadDownload Q249599_W2K_SP1_X86_NL.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19993)
French
DownloadDownload Q249599_W2K_SP1_X86_FR.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19989)
German
DownloadDownload Q249599_W2K_SP1_X86_DE.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19986)
Hebrew
DownloadDownload Q249599_W2K_SP1_X86_HE.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19996)
Italian
DownloadDownload Q249599_W2K_SP1_X86_IT.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19990)
Japanese
DownloadDownload Q249599_W2K_SP1_X86_JA.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19991)
Korean
DownloadDownload Q249599_W2K_SP1_X86_KO.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19992)
Portuguese (Brazil)
DownloadDownload Q249599_W2K_SP1_X86_BR.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19984)
Spanish
DownloadDownload Q249599_W2K_SP1_X86_ES.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19988)
Swedish
DownloadDownload Q249599_W2K_SP1_X86_SV.EXE now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=19994)
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.
Windows NT 4.0
--------------
The following files are available for download from the Microsoft Download
Center:
US English
x86: DownloadDownload Uncsec4i.exe now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=18900)
Alpha: DownloadDownload Uncsec4a.exe now
(http://www.microsoft.com/Downloads/Release.asp?ReleaseID=18901)
Dutch
x86: Download Uncsec4i.exe now
(http://download.microsoft.com/download/iis40/Patch/4.2.736.1/NT4/NL/Uncsec4i.exe)
Alpha: Download Uncsec4a.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/alpha/nl/Uncsec4a.exe)
French
x86: Download Uncsec4i.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/nt4/fr/Uncsec4i.exe)
Alpha: Download Uncsec4a.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/alpha/fr/Uncsec4a.exe)
German
x86: Download Uncsec4i.exe now
(http://download.microsoft.com/download/iis40/Patch/4.2.736.1/NT4ALPHA/DE/Uncsec4i.exe)
Alpha: Download Uncsec4a.exe now
(http://download.microsoft.com/download/iis40/Patch/4.2.736.1/NT4ALPHA/DE/Uncsec4a.exe)
NOTE: Debug symbol files are required by an administrator to do both kernel
and user mode debugging, providing a method to resolve global variables and
function names in the loaded executable file. Click the file names below to
download the symbol files:
German x86 Symbols: Download Uncsec4is.exe now
(http://download.microsoft.com/download/iis40/Patch/4.2.736.1/NT4ALPHA/DE/Uncsec4is.exe)
German Alpha Symbols: Download Uncsec4as.exe now
(http://download.microsoft.com/download/iis40/Patch/4.2.736.1/NT4ALPHA/DE/Uncsec4as.exe)
Portuguese (Brazilian)
x86: DownloadDownload Uncsec4i.exe now (
http://download.microsoft.com/download/iis40/patch/4.2.736.1/nt4/pt-br/Uncsec4i.exe)
Alpha: Download Uncsec4a.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/alpha/pt-br/Uncsec4a.exe)
Spanish
x86: Download Uncsec4i.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/nt4/es/Uncsec4i.exe)
Alpha: DownloadDownload Uncsec4a.exe now (
http://download.microsoft.com/download/iis40/patch/4.2.736.1/alpha/es/Uncsec4a.exe)
Swedish
x86: Download Uncsec4i.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/nt4/sv/Uncsec4i.exe)
Alpha: Download Uncsec4a.exe now
(http://download.microsoft.com/download/iis40/patch/4.2.736.1/alpha/sv/Uncsec4a.exe)
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 Platform
-------------------------------------------------------------
12/28/99 06:02p 4.2.736.1 185,248 Infocomm.dll x86
12/28/99 06:03p 4.2.736.1 38,256 Ssinc.dll x86
12/28/99 06:03p 4.2.736.1 25,360 Sspifilt.dll x86
12/28/99 06:03p 4.2.736.1 228,464 W3svc.dll x86
Microsoft Windows NT Server version 4.0, Terminal Server Edition
----------------------------------------------------------------
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 1.
Windows NT 4.0
--------------
Microsoft has confirmed this to be a problem in Internet Information Server 4.0.
MORE INFORMATION
================
There are significant restrictions that increase the difficulty of exploiting
this vulnerability:
- By design, virtual directories hide the actual location of files. Under most
circumstances, there is no way for an attacker to determine which files on a
server actually reside on a UNC share.
- Many browsers "correct" requests that contain the trailing characters at
issue here by either removing the characters or changing them.
- If recommended security practices are followed, ASP and other files that
require server-side processing will not contain any sensitive information to
compromise.
This fix eliminates the vulnerability by removing the trailing special characters
if they are included in the request. This causes the appropriate scripting
engine to process the file when the request is returned to the browser. If the
request is improperly formatted, the request is denied, and then returned to the
client as an invalid request.
For related information about this problem, please visit the following Microsoft
Web site:
http://www.microsoft.com/technet/security/bulletin/ms00-019.asp
For additional security-related information about Microsoft products, please
visit the following Microsoft Web site:
http://www.microsoft.com/security/
For additional information about how to install Windows 2000 and Windows 2000
hotfixes at the same time, click the article number below to view the article in
the Microsoft Knowledge Base:
Q249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes
Additional query words: tsesrp
======================================================================
Keywords : kbSecurity kbWin2000PreSP1Fix kbWinNT400PreSP7Fix kbgraphxlinkcritical
Technology : kbiisSearch kbiis500 kbiis400
Version : :4.0,5.0
Hardware : ALPHA x86
Issue type : kbbug
Solution Type : kbfix
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.