Microsoft Security Bulletin MS15-110 - Important

• 10/11/2017
• 14 minutes to read
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Security Updates for Microsoft Office to Address Remote Code Execution (3096440)

Published: October 13, 2015

Version: 1.0

Executive Summary

This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

This security update is rated Important for all supported editions of the following software:

• Microsoft Excel 2007, Microsoft Visio 2007
• Microsoft Excel 2010, Microsoft Visio 2010
• Microsoft Excel 2013, Microsoft Excel 2013 RT
• Microsoft Excel 2016
• Microsoft Excel for Mac 2011
• Microsoft Excel 2016 for Mac
• Microsoft Excel Viewer, Microsoft Office Compatibility Pack
• Excel Services on Microsoft SharePoint Server 2007
• Excel Services on Microsoft SharePoint Server 2010, Microsoft Web App 2010, Microsoft Excel Web App 2010
• Excel Services on Microsoft SharePoint Server 2013, Microsoft Office Web Apps Server 2013
• Microsoft SharePoint Server 2007
• Microsoft SharePoint Server 2010
• Microsoft SharePoint Server 2013, Microsoft SharePoint Foundation 2013

For more information, see the Affected Software and Vulnerability Severity Ratings section.

The security update addresses the vulnerabilities by:

• Correcting how Office handles objects in memory
• Ensuring that SharePoint InfoPath Forms Services properly handles DTD entities
• Helping to ensure that Office Web Apps Server properly sanitizes web requests
• Modifying the way that SharePoint sanitizes web requests

For more information about the vulnerabilities, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3096440. 

Affected Software and Vulnerability Severity Ratings

The following software versions or editions are affected. Versions or editions that are not listed are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, see Microsoft Support Lifecycle.

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the October bulletin summary.  

Microsoft Office Software

*The Updates Replaced column shows only the latest update in a chain of superseded updates. For a comprehensive list of updates replaced, go to the Microsoft Update Catalog, search for the update KB number, and then view update details (updates replaced information is on the Package Details tab).

Microsoft Office Services and Web Apps

Microsoft Server Software

Update FAQ

Does this update contain any additional security-related changes to functionality?
Yes. In addition to the changes that are listed for the vulnerabilities described in this bulletin, this update includes defense-in-depth updates to help make Microsoft Office more secure.

I am being offered this update for software that is not specifically indicated as being affected in the Affected Software and Vulnerability Severity Ratings table. Why am I being offered this update?
When updates address vulnerable code that exists in a component that is shared between multiple Microsoft Office products or shared between multiple versions of the same Microsoft Office product, the update is considered to be applicable to all supported products and versions that contain the vulnerable component.

For example, when an update applies to Microsoft Office 2007 products, only Microsoft Office 2007 may be specifically listed in the Affected Software table. However, the update could apply to Microsoft Word 2007, Microsoft Excel 2007, Microsoft Visio 2007, Microsoft Compatibility Pack, Microsoft Excel Viewer, or any other Microsoft Office 2007 product that is not specifically listed in the Affected Software table.

For example, when an update applies to Microsoft Office 2010 products, only Microsoft Office 2010 may be specifically listed in the Affected Software table. However, the update could apply to Microsoft Word 2010, Microsoft Excel 2010, Microsoft Visio 2010, Microsoft Visio Viewer, or any other Microsoft Office 2010 product that is not specifically listed in the Affected Software table.

For example, when an update applies to Microsoft Office 2013 products, only Microsoft Office 2013 may be specifically listed in the Affected Software table. However, the update could apply to Microsoft Word 2013, Microsoft Excel 2013, Microsoft Visio 2013, or any other Microsoft Office 2013 product that is not specifically listed in the Affected Software table.

Vulnerability Information

Multiple Microsoft Office Memory Corruption Vulnerabilities

Remote code execution vulnerabilities exist in Microsoft Office software when the Office software fails to properly handle objects in memory. An attacker who successfully exploited these vulnerabilities could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then 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.

Exploitation of these vulnerabilities requires that a user open a specially crafted file with an affected version of Microsoft Office software. In an email attack scenario an attacker could exploit the vulnerabilities by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file that is designed to exploit the vulnerabilities. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or Instant Messenger message, and then convince them to open the specially crafted file.

The security update addresses the vulnerabilities by correcting how Office handles objects in memory.

The following tables contain links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list: