__________________________________________________________

                       The U.S. Department of Energy
                   Computer Incident Advisory Capability
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             __________________________________________________________

                             INFORMATION BULLETIN

         Microsoft Unchecked Buffer in Windows Redirector Vulnerability
                     [Microsoft Security Bulletin MS03-005]

February 6, 2003 18:00 GMT                                        Number N-039
______________________________________________________________________________
PROBLEM:       The Windows Redirector is used by a Windows client to access
               files, whether local or remote, regardless of the underlying
               network protocols in use. A vulnerability exists in the
               implementation of the Windows Redirector on Windows XP because
               an unchecked buffer is used to receive parameter information.
PLATFORM:      Microsoft Windows XP
DAMAGE:        By providing malformed data to the Windows Redirector, an
               attacker could possibly cause the system to fail, or if the
               data was crafted in a particular way, could run code of the
               attacker’s choice.
SOLUTION:      Apply available patches.
______________________________________________________________________________
VULNERABILITY  The risk is MEDIUM. This vulnerability cannot be exploited
ASSESSMENT:    remotely. An attacker would require the ability to log onto the
               system interactively in order to run programs that use the
               Windows Redirector. Windows XP systems that are not shared
               between users would not be at risk.
______________________________________________________________________________
LINKS:
 CIAC BULLETIN:      http://www.ciac.org/ciac/bulletins/n-039.shtml
 ORIGINAL BULLETIN:
                     http://www.microsoft.com/technet/treeview/default.asp?url=
                       /technet/security/bulletin/MS03-005.asp
 PATCHES:            32-bit Edition:
                     http://microsoft.com/downloads/details.aspx?FamilyId=
                       33DABD1F-505E-48ED-B9BD-CDAC0F8A2BC1&displaylang=en
                     64-bit Edition:
                     http://microsoft.com/downloads/details.aspx?FamilyId=
                       A2258F4E-9A69-4537-9469-0DDEB4BB76F8&displaylang=en
______________________________________________________________________________
[***** Start Microsoft Security Bulletin MS03-005 *****]

Microsoft Security Bulletin MS03-005   

Unchecked Buffer in Windows Redirector Could Allow Privilege Elevation (810577)
Originally posted: February 5, 2003

Summary
Who should read this bulletin: Customers using Microsoft® Windows® XP. 

Impact of vulnerability: Local elevation of privileges 

Maximum Severity Rating: Important 

Recommendation: Customers should consider applying the patch. 

Affected Software: 

Microsoft Windows XP 

Technical details

Technical description: 

The Windows Redirector is used by a Windows client to access files, whether 
local or remote, regardless of the underlying network protocols in use. For 
example, the "Add a Network Place" Wizard or the NET USE command can be used 
to map a network share as a local drive, and the Windows Redirector will 
handle the routing of information to and from the network share.

A security vulnerability exists in the implementation of the Windows 
Redirector on Windows XP because an unchecked buffer is used to receive 
parameter information. By providing malformed data to the Windows Redirector, 
an attacker could cause the system to fail, or if the data was crafted in 
a particular way, could run code of the attacker’s choice. 


Mitigating factors: 

An attacker would require the ability to log onto the system interactively 
in order to run programs that use the Windows Redirector. This vulnerability 
cannot be exploited remotely. 

Windows XP systems that are not shared between users would not be at risk.
 
Severity Rating: Windows XP Important 

The above assessment is based on the types of systems affected by the 
vulnerability, their typical deployment patterns, and the effect that 
exploiting the vulnerability would have on them. 

Vulnerability identifier: CAN-2003-0004 

Tested Versions:
Microsoft tested Windows XP to assess whether it is affected by these 
vulnerabilities. Windows NT 4.0, Windows NT 4.0, Terminal Server Edition, 
and Windows 2000 do not contain the code in question and are not affected 
by this vulnerability.

Patch availability

Download locations for this patch 
Windows XP:

32-bit Edition 
64-bit Edition 

Additional information about this patch

Installation platforms: 

This patch can be installed on systems running Windows XP Gold and Windows 
XP Service Pack 1. 

Inclusion in future service packs:
The fix for this issue will be included in Windows XP Service Pack 2. 

Reboot needed: Yes 

Patch can be uninstalled: Yes 

Superseded patches: None. 

Verifying patch installation: 

Windows XP Gold:
To verify that the patch has been installed on the machine, confirm that 
the following registry key has been created on the machine: 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP1\Q810577

To verify the individual files, use the date/time and version information 
provided in the following registry key: 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP1\Q810577\Filelist 

Windows XP Service Pack 1:
To verify that the patch has been installed on the machine, confirm that 
the following registry key has been created on the machine: 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP2\Q810577

To verify the individual files, use the date/time and version information 
provided in the following registry key: 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP2\Q810577\FilelistTo 

Caveats:
None 

Localization:
Localized versions of this patch are available at the locations discussed 
in "Patch Availability". 

Obtaining other security patches: 

Patches for other security issues are available from the following locations: 

Security patches are available from the Microsoft Download Center, and can 
be most easily found by doing a keyword search for "security_patch". 

Patches for consumer platforms are available from the WindowsUpdate web site 

Other information: 

Acknowledgments

Microsoft thanks  NSFocus for reporting this issue to us and working with us 
to protect customers. 

Support: 

Microsoft Knowledge Base article 810577 discusses this issue and will be 
available approximately 24 hours after the release of this bulletin. 
Knowledge Base articles can be found on the Microsoft Online Support web 
site. 

Technical support is available from Microsoft Product Support Services. 
There is no charge for support calls associated with security patches. 

Security Resources: The Microsoft TechNet Security Web Site provides 
additional information about security in Microsoft products. 

Disclaimer: 
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. 

Revisions: 

V1.0 February 5, 2003: Bulletin Created. 

[***** End Microsoft Security Bulletin MS03-005 *****]
_______________________________________________________________________________

CIAC wishes to acknowledge the contributions of Microsoft Corporation for the
information contained in this bulletin.
_______________________________________________________________________________

CIAC, the Computer Incident Advisory Capability, is the computer
security incident response team for the U.S. Department of Energy
(DOE) and the emergency backup response team for the National
Institutes of Health (NIH). CIAC is located at the Lawrence Livermore
National Laboratory in Livermore, California. CIAC is also a founding
member of FIRST, the Forum of Incident Response and Security Teams, a
global organization established to foster cooperation and coordination
among computer security teams worldwide.

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This document was prepared as an account of work sponsored by an
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Government nor the University of California nor any of their
employees, makes any warranty, express or implied, or assumes any
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