Fix for SMB DOS attack posted

Paul Leach (paulle@MICROSOFT.COM)
Fri, 13 Feb 1998 16:49:14 -0800

A hot-fix for a DOS attack on NT file servers that had not been previously
publically known has been posted. The following is the KB article on the
fix.

DOCUMENT: Q180963
TITLE :Denial of Service Attack Causes Windows NT Systems to Reboot
PRODUCT :Microsoft Windows NT
PROD/VER:4.00
OPER/SYS:WINDOWS
KEYWORDS:kbbug4.00 kbfix4.00 NTSrv ntstop

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0
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SYMPTOMS
========

During the processing of a Server Message Block (SMB) logon request, memory
corruption occurs causing one of the following errors:

STOP 0x0000000A
STOP 0x00000050

The result is a system reboot or system hang.

Note: The Stop errors will vary from case to case.

CAUSE
=====

The size of data to follow is contained in the SMB logon request. When the
size specified in the request does not match the size actually present,
corruption occurs.

RESOLUTION
==========

To resolve this problem, obtain the following fix or wait for the next
Windows NT 4.0 service pack.

This fix should have the following time stamp:

01/07/98 07:59p 229,840 Srv.sys (Intel)

01/07/98 07:56p 466,384 Srv.sys (Alpha)

This hotfix has been posted to the following Internet location:

ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/
hotfixes-postSP3/srv-fix

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

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 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: 4.00 ntstop
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