This security update resolves multiple privately reported vulnerabilities in Microsoft Office server software. These vulnerabilities could allow remote code execution if an authenticated attacker sends specially crafted page content to a SharePoint server. An attacker who successfully exploited these vulnerabilities could run arbitrary code in the security context of the W3WP service account on the target SharePoint site.
This security update is rated Important for supported editions of Microsoft SharePoint Server 2013 and for affected Microsoft Office Services and Web Apps on supported editions of Microsoft SharePoint Server 2010 and Microsoft SharePoint Server 2013. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update addresses the vulnerabilities by correcting how SharePoint server sanitizes specially crafted page content. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability 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, 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.