A Program that Passes Invalid Screen Size Parameters Causes an Access Violation (311486)



The information in this article applies to:

  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Advanced Server SP1
  • Microsoft Windows 2000 Advanced Server SP2
  • Microsoft Windows 2000 Professional SP1
  • Microsoft Windows 2000 Professional SP2
  • Microsoft Windows XP Home Edition
  • Microsoft Windows XP Professional

This article was previously published under Q311486

SYMPTOMS

The versions of Windows listed at the beginning of this article contain the following vulnerability: When you run a local program that passes invalid parameters that are smaller than the screen size, this causes an access violation (AV). As a result, Windows stops responding (crashes).

Sample Code

The following uncompiled sample code is known to cause this behavior:
#include <stdio.h>

int main(void)
{
while(1)
printf("\t\t\b\b\b\b\b\b");
return 0;
}
				

CAUSE

This behavior occurs because Windows checks invalid parameters that are larger than the screen size, but does not currently check invalid parameters that are smaller than the screen size.

RESOLUTION

Windows XP

To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to Obtain the Latest Windows XP Service Pack

The English-language version of this fix should have the following file attributes or later:
   Date         Time   Version      Size     File name
   ----------------------------------------------------
   02-Nov-2001  21:43  5.1.2600.19  272,384  Winsrv.dll
   02-Nov-2001  21:43  5.1.2600.19  272,384  Winsrv.dll
				

Windows 2000

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English-language version of this fix should have the following file attributes or later:
   Date         Time   Version        Size       File name
   ----------------------------------------------------------
   05-Nov-2001  18:57  5.0.2195.4572    222,480  Gdi32.dll
   05-Nov-2001  18:57  5.0.2195.4272    731,920  Kernel32.dll
   25-Jun-2001  18:17  3.10.0.103        47,808  User.exe
   05-Nov-2001  18:57  5.0.2195.4314    402,192  User32.dll
   05-Nov-2001  18:57  5.0.2195.4345    371,984  Userenv.dll
   27-Sep-2001  15:00  5.0.2195.4426  1,731,536  Win32k.sys
   30-Oct-2001  18:17  5.0.2195.4575    178,960  Winlogon.exe
   05-Nov-2001  18:58  5.0.2195.4553    243,472  Winsrv.dll
   05-Nov-2001  18:58  5.0.2195.4272    731,920  Kernel32.dll
   05-Nov-2001  18:58  5.0.2195.4426  1,731,536  Win32k.sys
   05-Nov-2001  18:58  5.0.2195.4553    243,472  Winsrv.dll
				

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Microsoft Windows 2000 Service Pack 3 (SP3) and Microsoft Windows XP Service Pack 1 (SP1).

MORE INFORMATION

This update causes Windows to check lower boundaries. The Winsrv.dll file is directly affected by this update, but the following files are included because of dependency issues:

User.exe
User32.dll
Win32k.sys
Gdi32.dll
Userenv.dll
Kernel32.dll
Winlogon.exe


Modification Type:MinorLast Reviewed:9/26/2005
Keywords:kbHotfixServer kbQFE kbbug kbfix kbSecurity kbshell kbWin2000PreSP3Fix kbWin2000sp3fix kbWinXPsp1fix KB311486