Conference decwet::windows-nt

6000.0. "OOB TCP/IP Crash (winnuke) Fix" by PYRO::RON (Ron S. van Zuylen) Tue May 13 1997 01:13

There is a newly discovered bug in Microsoft's TCP/IP implementation that can
allow malicious users to crash any Windows NT systems.  (The bug is also in
Windows 95, to my knowledge, but no patch has been released... yet.)  The
original code that exploited the bug was called "winnuke.c"
 
Microsoft has released a fix for Windows NT.  It works.  I've attached the
information.

--Ron


DOCUMENT:Q143478    [winnt]
TITLE   :Stop 0A in TCPIP.SYS When Receiving Out Of Band (OOB) Data
PRODUCT :Microsoft Windows NT
PROD/VER:3.51 4.00
OPER/SYS:WINDOWS
KEYWORDS:kbbug3.51 kbbug4.00 kbfile kbfix3.51 kbfix4.00 NTSrvWkst nttcp

--------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Windows NT Workstation versions 3.51 and 4.0
 - Microsoft Windows NT Server versions 3.51 and 4.0
--------------------------------------------------------------------------

SYMPTOMS
========

A Stop 0x0000000A occurs in Tcpip.sys when receiving Out of Band (OOB)
data.

CAUSE
=====

A sender specifies "Out of Band" data by setting the URGENT bit flag in the
TCP header. The receiver uses the URGENT POINTER to determine where in the
segment the urgent data ends. Windows NT bugchecks when the URGENT POINTER
points to the end of the frame and no normal data follows. Windows NT
expects normal data to follow.

RESOLUTION
==========

Microsoft has updated Tcpip.sys to correct the problem. Instructions for
installing it are available from Microsoft support channels, or directly
from the following Internet locations:

Windows NT 4.0
--------------

This hotfix has been posted to the following Internet location:

ftp://ftp.microsoft.com/
  bussys/winnt/winnt-public/fixes/usa/NT40/hotfixes-postSP2/oob-fix

NOTE: Service pack 2 must be applied to Windows NT 4.0 prior to applying
this fix.

Windows NT 3.51
---------------

This hotfix has been posted to the following Internet location:

 
ftp://ftp.microsoft.com/
  bussys/winnt/winnt-public/fixes/usa/NT351/hotfixes-postSP5/oob-fix

NOTE: Service pack 5 must be applied to Windows NT 3.51 prior to applying
this fix.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 3.51 and 
4.0. A supported fix is now available, but has not been fully regression-tested
and should be applied only to systems experiencing this specific problem.
Unless you are severely impacted by this specific problem, Microsoft
recommends that you wait for the next Service Pack that contains this fix.
Contact Microsoft Technical Support for more information.

Additional query words: prodnt 4.00 3.51 

============================================================================

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SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1997.
    

    The original OOB patch has been updated.  (The first patch fixed most
    of the vulnerability... but not all.)

    The patches are in the same places as before.
    
    Microsoft now has a new patch for Service Pack 3, which only has the
    "older" OOB fix, at:
    
    ftp://ftp.microsoft.com/
      bussys/winnt/winnt-public/fixes/usa/nt40/hotfixes-postSP3/oob-fix
    
    --Ron