MS14-055: Vulnerabilities in Lync could allow denial of service: September 9, 2014

Microsoft released an update to Lync Server 2013 (Build 8308.803) that address vulnerabilities in Lync Server which can cause denial of service.

This update replaces CU5 (Build 8308.738 which released in August 2014).

• KB: https://support.microsoft.com/kb/2990928
• Source: Microsoft Security Bulletin MS14-055 – Important
• Download: Security Update for Lync Server 2013 (KB2986072, KB2982389, KB2992965, KB2982390)
• Latest updates for Lync Server 2013: http://support.microsoft.com/kb/2809243

General Information

Executive Summary

This security update resolves three privately reported vulnerabilities in Microsoft Lync Server. The most severe of these vulnerabilities could allow denial of service if an attacker sends a specially crafted request to a Lync server.

This security update is rated Important for all supported editions of Microsoft Lync Server 2010 and Microsoft Lync Server 2013. For more information, see the Affected and Non-Affected Software section.

The security update addresses the vulnerabilities by correcting the way Lync Server sanitizes user input and by correcting the way Lync Server handles exceptions and null dereferences. For more information about these vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability later in this bulletin.

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, see Microsoft Knowledge Base Article 294871.

For administrators and enterprise installations, or end users who want to install this security update manually (including customers who have not enabled automatic updating), 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. The updates are also available via the download links in the Affected Software table later in this bulletin.

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

Knowledge Base Article

• Knowledge Base Article: 2990928
• File Information: Yes
• SHA1/SHA2 hashes: Yes
• Known issues: Yes