DOCUMENT:Q238349
TITLE   :Specially-Malformed Header in GET Request Creates Denial of Service
PRODUCT :IIS
PROD/VER:4.0
OPER/SYS:WINDOWS NT
KEYWORD :kbbug4.00 kbfix4.00 

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The information in this article applies to:

 - Microsoft Internet Information Server version 4.0 
 - Microsoft Site Server version 3.0 
 - Microsoft Commercial Internet System versions 2.0, 2.5 
 - Microsoft Site Server version 3.0, Commerce Edition 
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SYMPTOMS
========

A specially-malformed header in a GET request can create a Denial of Service in
the W3 server and use all available memory on the Web server, causing Internet
Information Server (IIS) to stop responding to any request.

RESOLUTION
==========

A supported fix that corrects this problem is now available from Microsoft, but
it has not been fully regression tested and should be applied only to systems
experiencing this specific problem. If you are not severely affected by this
specific problem, Microsoft recommends that you wait for the next Windows NT
service pack that contains this fix.

To resolve this problem immediately, 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://www.microsoft.com/support/supportnet/overview/overview.asp

The English version of this fix should have the following file attributes or
later:

   Date      Time                 Size    File name     Platform
   -------------------------------------------------------------
   08/11/99  11:03p               328,512 asp.dll       x86
   08/11/99  11:01p                43,456 coadmin.dll   x86
   08/11/99  11:03p                11,168 ftpctrs2.dll  x86
   08/11/99  11:03p                81,888 ftpsvc2.dll   x86
   08/11/99  10:06p                11,396 httpext.h     x86
   08/11/99  11:02p                17,424 iisadmin.dll  x86
   08/11/99  11:01p                62,960 iislog.dll    x86
   08/11/99  11:01p                16,848 infoadmn.dll  x86
   08/11/99  11:01p               184,736 infocomm.dll  x86
   08/11/99  11:01p                29,520 iscomlog.dll  x86
   08/11/99  11:02p                11,248 iwrps.dll     x86
   08/11/99  11:01p                71,232 metadata.dll  x86
   08/11/99  11:02p                51,296 nsepm.dll     x86
   09/17/98  07:26p                   992 rmiisupd.cmd  x86
   08/11/99  11:02p                14,752 w3ctrs.dll    x86
   08/11/99  11:02p               229,008 w3svc.dll     x86
   08/11/99  11:02p                87,504 wam.dll       x86

   08/11/99  10:55p               549,136 asp.dll       Alpha
   08/11/99  10:53p                77,072 coadmin.dll   Alpha
   08/11/99  10:54p                17,168 ftpctrs2.dll  Alpha
   08/11/99  10:54p               126,736 ftpsvc2.dll   Alpha
   08/11/99  10:08p                11,396 httpext.h     Alpha
   08/11/99  10:54p                28,432 iisadmin.dll  Alpha
   08/11/99  10:53p               112,400 iislog.dll    Alpha
   08/11/99  10:53p                25,872 infoadmn.dll  Alpha
   08/11/99  10:53p               303,888 infocomm.dll  Alpha
   08/11/99  10:53p                45,840 iscomlog.dll  Alpha
   08/11/99  10:54p                16,656 iwrps.dll     Alpha
   08/11/99  10:53p               131,856 metadata.dll  Alpha
   08/11/99  10:54p                87,824 nsepm.dll     Alpha
   01/25/99  06:43p                   992 rmiisupd.cmd  Alpha
   08/11/99  10:54p                21,264 w3ctrs.dll    Alpha
   08/11/99  10:54p               385,296 w3svc.dll     Alpha
   08/11/99  10:54p               149,264 wam.dll       Alpha

This hotfix has been posted to the following Internet location as Vdext4i.exe
(x86) and Vdext4a.exe (Alpha):

   ftp://ftp.microsoft.com/bussys/iis/iis-public/fixes/usa/security/hdbrk-fix/

NOTE: If this product was already installed on your computer when you purchased
it from the Original Equipment Manufacturer (OEM) and you need this fix, please
call the Pay Per Incident number listed on the above Web site. If you contact
Microsoft to obtain this fix, and if it is determined that you only require the
fix you requested, no fee will be charged. However, if you request additional
technical support, and if your no-charge technical support period has expired,
or if you are not eligible for standard no-charge technical support, you may be
charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the
following article in the Microsoft Knowledge Base:

   Q154871 Determining If You Are Eligible for No-Charge Technical Support

STATUS
======

Microsoft has confirmed this to be a problem in Internet Information Server 4.0.

Additional query words:
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