This security update resolves a privately reported vulnerability in the Windows Internet Name Service (WINS). The vulnerability could allow elevation of privilege if a user received a specially crafted WINS replication packet on an affected system running the WINS service. An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

This security update is rated Important for servers running supported editions of Windows Server 2003, Windows Server 2008 (except Itanium), and Windows Server 2008 R2 (except Itanium), on which WINS is installed. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the way WINS handles internal communication on the loopback address. 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.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. None

Reference: http://www.microsoft.com/technet/security/Bulletin/MS11-070.mspx