=====================================================================
                                   CERT-Renater

                        Note d'Information No. 2009/VULN333
_____________________________________________________________________

DATE                      : 13/08/2009

HARDWARE PLATFORM(S)      : /

OPERATING SYSTEM(S)       : Windows 2000, Windows XP,Windows Server 2003,
                             Windows Vista Windows Server 2008
                              running Microsoft Telnet.

======================================================================
KB960859
http://www.microsoft.com/technet/security/bulletin/MS09-042.mspx
______________________________________________________________________
Microsoft Security Bulletin MS09-042 - Important

Vulnerability in Telnet Could Allow Remote Code Execution (960859)

   Published: August 11, 2009

   Version: 1.0

General Information

Executive Summary

   This security update resolves a publicly disclosed vulnerability in
   the Microsoft Telnet service. The vulnerability could allow an
   attacker to obtain credentials and then use them to log back into
   affected systems. The attacker would then acquire user rights on a
   system identical to the user rights of the logged-on user. This
   scenario could ultimately result in remote code execution on affected
   systems. An attacker who successfully exploited this vulnerability
   could install programs; view, change, or delete data; or create new
   accounts with full user rights. Users whose accounts are configured to
   have fewer user rights on the system could be less impacted than users
   who operate with administrative user rights.

   This security update is rated Important for all supported editions of
   Microsoft Windows 2000, Windows XP, and Windows Server 2003, and
   Moderate for all supported editions of Windows Vista and Windows
   Server 2008. For more information, see the subsection, Affected and
   Non-Affected Software, in this section.

   The security update addresses the vulnerability by modifying the way
   that the Telnet service validates authentication replies in order to
   prevent the relay of credentials. For more information about the
   vulnerability, see the Frequently Asked Questions (FAQ) subsection for
   the specific vulnerability entry under the next section, Vulnerability
   Information.

   Recommendation. The majority of customers have automatic updating
   enabled and will not need to take any action because this security
   update will be downloaded and installed automatically. Customers who
   have not enabled automatic updating need to check for updates and
   install this update manually. For information about specific
   configuration options in automatic updating, see Microsoft
   Knowledge Base Article 294871.

   For administrators and enterprise installations, or end users who want
   to install this security update manually, Microsoft recommends that
   customers apply the update at the earliest opportunity using update
   management software, or by checking for updates using the
   Microsoft Update service.

   Known Issues. None.

Affected Software

   Microsoft Windows 2000 Service Pack 4 (KB960859)
   Windows XP Service Pack 2 and Windows XP Service Pack 3 (KB960859)
   Windows XP Professional x64 Edition Service Pack 2 (KB960859)
   Windows Server 2003 Service Pack 2 (KB960859)
   Windows Server 2003 x64 Edition Service Pack 2 (KB960859)
   Windows Server 2003 with SP2 for Itanium-based Systems (KB960859)
   Windows Vista, Windows Vista Service Pack 1, and Windows Vista
     Service Pack 2 (KB960859)
   Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack
     1, and Windows Vista x64 Edition Service Pack 2 (KB960859)
   Windows Server 2008 for 32-bit Systems and Windows Server 2008 for
     32-bit Systems Service Pack 2* (KB960859)
   Windows Server 2008 for x64-based Systems and Windows Server 2008
     for x64-based Systems Service Pack 2* (KB960859)
   Windows Server 2008 for Itanium-based Systems and Windows Server
     2008 for Itanium-based Systems Service Pack 2 (KB960859)

Vulnerability Information

Telnet Credential Reflection Vulnerability - CVE-2009-1930

   A remote code execution vulnerability exists in the Microsoft Telnet
   service. An attacker who successfully exploited this vulnerability
   could install programs; view, change, or delete data; or create new
   accounts with full user rights. Users whose accounts are configured to
   have fewer user rights on the system could be less impacted than users
   who operate with administrative user rights.


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

          =========================================================
          Les serveurs de référence du CERT-Renater
          http://www.urec.fr/securite
          http://www.cru.fr/securite
          http://www.renater.fr
          =========================================================
          + CERT-RENATER          | tel : 01-53-94-20-44          +
          + 151 bd de l'Hopital   | fax : 01-53-94-20-41          +
          + 75013 Paris           | email: certsvp@renater.fr     +
          =========================================================