Microsoft Security Bulletin MS13-105 - Critical

Executive Summary

This security update resolves three publicly disclosed vulnerabilities and one privately reported vulnerability in Microsoft Exchange Server. The most severe of these vulnerabilities exist in the WebReady Document Viewing and Data Loss Prevention features of Microsoft Exchange Server. These vulnerabilities could allow remote code execution in the security context of the LocalService account if an attacker sends an email message containing a specially crafted file to a user on an affected Exchange server. The LocalService account has minimum privileges on the local system and presents anonymous credentials on the network.

This security update is rated Critical for all supported editions of Microsoft Exchange Server 2007, Microsoft Exchange Server 2010, and Microsoft Exchange Server 2013. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerabilities by updating the affected Oracle Outside In libraries to a non-vulnerable version, by enabling machine authentication check (MAC) according to best practices, and by ensuring that URLs are properly sanitized. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerabilities entry under the next section, Vulnerability Information.

Recommendation. Customers can configure automatic updating to check online for updates from Microsoft Update by using the Microsoft Update service. Customers who have automatic updating enabled and configured to check online for updates from Microsoft Update typically 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 from Microsoft Update and install this update manually. For information about specific configuration options in automatic updating in supported editions of Windows XP and Windows Server 2003, see Microsoft Knowledge Base Article 294871. For information about automatic updating in supported editions of Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2, see Understanding Windows automatic updating.

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

For more information go to: technet.microsoft.com