----------------------------------------------------------------------
Title:      Buffer Overrun in Windows Kernel Message Handling could
            Lead to Elevated Privileges (811493)
Date:       16 April 2003
Software:   Microsoft Windows NT 4.0, Windows 2000, and Windows XP
Impact:     Local Elevation of Privilege
Max Risk:   Important
Bulletin:   MS03-013

Microsoft encourages customers to review the Security Bulletins at:
http://www.microsoft.com/technet/security/bulletin/MS03-013.asp
http://www.microsoft.com/security/security_bulletins/ms03-013.asp
----------------------------------------------------------------------

Issue:
======
The Windows kernel is the core of the operating system. It provides
system level services such as device and memory management,
allocates processor time to processes and manages error handling.

There is a flaw in the way the kernel passes error messages to a
debugger. A vulnerability results because an attacker could write a
program to exploit this flaw and run code of their choice. An
attacker could exploit this vulnerability to take any action on the
system including deleting data, adding accounts with administrative
access, or reconfiguring the system.

For an attack to be successful, an attacker would need to be able
to logon interactively to the system, either at the console or
through a terminal session. Also, a successful attack would require
the introduction of code in order to exploit this vulnerability.
Because best practices recommends restricting the ability to logon
interactively on servers, this issue most directly affects client
systems and terminal servers.

Mitigating Factors:
====================
- A successful attack requires the ability to logon
  interactively to the target machine, either directly at the console
  or through a terminal session.
- Properly secured servers would be at little risk from this
  vulnerability. Standard best practices recommend only allowing
  trusted administrators to log onto such systems interactively;
  without such privileges, an attacker could not exploit the
  vulnerability.

Risk Rating:
============
Important

Patch Availability:
===================
 - A patch is available to fix this vulnerability. Please read the
   Security Bulletins at
   http://www.microsoft.com/technet/security/bulletin/ms03-013.asp
   http://www.microsoft.com/security/security_bulletins/ms03-013.asp

   for information on obtaining this patch.

Acknowledgment:
===============
 - Oded Horovitz of Entercept Security Technologies -
http://www.entercept.com
---------------------------------------------------------------------

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE
FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.


*******************************************************************