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Q106524: Invalid Named Pipe Message Causes SNABASE.EXE Exception

Article: Q106524
Product(s): Microsoft SNA Server
Version(s): WINDOWS:2.0,2.1,2.11
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 15-JUN-2001

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The information in this article applies to:

- Microsoft SNA Server, versions 2.0, 2.1, 2.11, on platform(s):
   - the operating system: Microsoft Windows NT 
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SYMPTOMS
========

SNA Server generates a Dr. Watson error in SNABASE.EXE when it receives an
invalid message over a Named Pipe connection from a client. The SNA Server also
logs an Event ID 624 in the Windows NT Application Log (as shown in the Event
Viewer) indicating that an SNADUMP.LOG was created for SNABASE.EXE. The
following is an excerpt from a DRWTSN32.LOG that is created following one of
these SNABASE errors:

  Application exception occurred:
  App: snabase.DBG (pid=148)
  When: 10/31/1995 @ 11:29:1.2
  Exception number: c0000005 (access violation)

NOTE: Your DRWTSN32.LOG file will appear somewhat different than this example.


CAUSE
=====

SNABASE.EXE on the SNA Server is not properly handling an invalid incoming
NewPipe messages from SNA Server clients over Named Pipe connections. The
NewPipe messages are only sent to the SNA Server when the WNAP (16-bit) or
SNABASE (32-bit) process is initializing on SNA Server clients.


RESOLUTION
==========

Microsoft has updated the following files to correct this problem:

  <winroot>\SYSTEM\SNALM.DLL
  <winroot>\SYSTEM\SNAIP.DLL
  <winroot>\SYSTEM\SNANW.DLL
  <winroot>\SYSTEM\SNAAT.DLL
  <winroot>\SYSTEM\SNABV.DLL
  <winroot>\SYSTEM\SNANB.DLL

These corrected files increase validity checking on incoming NewPipe messages
received from clients over Named Pipe connections as well as the other
client/server protocols supported by SNA Server. In addition, SNA Server now
logs an Event 631 in the Application Log when it receives an invalid NewPipe
message from a client.

STATUS
======

Microsoft has confirmed this to be a problem in SNA Server for Windows NT. This
problem was corrected in the latest SNA Server for Windows NT, 2.11 U.S. Service
Pack. For information on obtaining the Service Pack, query on the following word
in the Microsoft Knowledge Base (without the spaces):

  S E R V P A C K

MORE INFORMATION
================

For Win 3.x clients, a potential workaround is to start WNAP in advance (by
adding WNAP.EXE to the startup group of Windows or Windows for Workgroups), so
that it's not automatically invoked when an SNA application or emulator is
started.

Additional query words: prodsna

======================================================================
Keywords          : kbnetwork 
Technology        : kbAudDeveloper kbSNAServSearch
Version           : WINDOWS:2.0,2.1,2.11
Issue type        : kbbug

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

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