Specially-Malformed GET Requests Can Create a Denial of Service in W3 Server

ID: Q192296

The information in this article applies to:

SYMPTOMS

Specially-malformed GET requests can create a Denial of Service in the W3 server and use all available memory on the Web server, which causes Internet Information Server (IIS) to stop responding or generate an Access Violation error message.


RESOLUTION



A supported fix that corrects this problem is now available from Microsoft, but 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.

To resolve this problem immediately, download the fix as described below. 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/support/supportnet/default.asp

The English version of this fix for IIS 4.0 should have the following file attributes or later: 

   Date      Time     Size    File Name     Platform
   --------------------------------------------------
   12/11/98  03:51p   327,472 asp.dll       (x86)
   12/11/98  03:51p    11,168 ftpctrs2.dll  (x86)
   12/11/98  03:51p    81,376 ftpsvc2.dll   (x86)
   12/11/98  03:52p   154,288 inetmgr.dll   (x86)
   12/11/98  03:50p    16,848 infoadmn.dll  (x86)
   12/11/98  03:50p   184,192 infocomm.dll  (x86)
   12/11/98  03:49p    47,936 isatq.dll     (x86)
   12/11/98  03:50p    14,752 w3ctrs.dll    (x86)
   12/11/98  03:50p   227,392 w3svc.dll     (x86)
   12/11/98  03:50p    87,504 wam.dll       (x86)

   12/11/98  03:57p   548,112 asp.dll       (Alpha)
   12/11/98  03:56p    17,168 ftpctrs2.dll  (Alpha)
   12/11/98  03:56p   126,224 ftpsvc2.dll   (Alpha)
   12/11/98  03:58p   253,200 inetmgr.dll   (Alpha)
   12/11/98  03:55p    25,872 infoadmn.dll  (Alpha)
   12/11/98  03:55p   302,864 infocomm.dll  (Alpha)
   12/11/98  03:54p    82,704 isatq.dll     (Alpha)
   12/11/98  03:56p    21,264 w3ctrs.dll    (Alpha)
   12/11/98  03:56p   381,200 w3svc.dll     (Alpha)
   12/11/98  03:55p   149,264 wam.dll       (Alpha)

The English version of this fix for IIS 3.0 should have the following file attributes or later: 

   Date      Time     Size    File Name     Platform
   --------------------------------------------------
   12/16/98  04:08p   130,320 Infocomm.dll  (x86)
   12/16/98  04:10p   113,936 W3svc.dll     (x86)

   12/16/98  04:08p   223,504 Infocomm.dll  (Alpha)
   12/16/98  04:11p   171,280 W3svc.dll     (Alpha)



The IIS 4.0 version of this hotfix has been posted to the following Internet location as Infget4i.exe (x86) and Infget4a.exe (Alpha):
ftp://ftp.microsoft.com/bussys/iis/iis-public/fixes/usa/security/Infget-fix/

NOTE: The above link is one path; it has been wrapped for readability.

The IIS 3.0 version of this hotfix must be installed over Windows NT 4.0, service pack 4, and has been posted to the following Internet location as Infget3i.exe (x86) and Infget3a.exe (Alpha):
ftp://ftp.microsoft.com/bussys/iis/iis-public/fixes/usa/security/Infget-fix/

NOTE: The above link is one path; it has been wrapped for readability.



NOTE: If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 : Determining If Your Product Is Eligible for No-Charge Technical Support


STATUS

Microsoft has confirmed this to be a problem in Internet Information Server versions 3.0 and 4.0.

Additional query words: IIS hotfix hot fix qfe quick fix engineering patch 


Keywords          : kbbug4.00 kbfix4.00 kbbug3.00 iissecurity iiswww kbfix3.00 
Version           : WinNT:3.0, 4.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: July 7, 1999