Security Update for Microsoft Office to Address Remote Code Execution (3124585)
Published: January 12, 2016 | Updated: January 13, 2016
Version: 1.1
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.
For more information, see the Affected Software and Vulnerability Severity Ratings section.
The security update addresses the vulnerabilities by:
Correcting how Microsoft Office handles objects in memory
Ensuring that Microsoft SharePoint correctly enforces ACP configuration settings
Helping to ensure that Microsoft Office properly implements the ASLR security feature
For more information about the vulnerabilities, see the Vulnerability Information section.
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 January bulletin summary.
Microsoft Office Software
Vulnerability Severity Rating and Maximum Security Impact by Affected 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*The Updates Replaced column shows only the latest update in a chain of superseded updates.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 Server Software
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
I have Microsoft Visual Basic 6.0 installed. Do I need to install the 3096896 update?
Yes, you need to install the 3096896 update to be protected from the vulnerability.
Does this update contain any additional security-related changes to functionality?
In addition to the changes that are listed for the vulnerabilities described in this bulletin, this update includes defense-in-depth updates to help improve security-related features.
I have Microsoft Word 2010 installed. Why am I not being offered the 3114554 update?
The 3114554 update only applies to systems running specific configurations of Microsoft Office 2010. Some configurations will not be offered the update.
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
Multiple 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.
To exploit the vulnerabilities, a user must open a specially crafted file with an affected version of Microsoft Office software. Note that for CVE-2016-0010 the Preview Pane is an attack vector for this vulnerability. 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:
Microsoft has not identified any mitigating factors for this vulnerability.
Workarounds
Microsoft has not identified any workarounds for these vulnerabilities.
Multiple Microsoft SharePoint Security Feature Bypasses
Multiple security feature bypasses exist in Microsoft SharePoint when Access Control Policy (ACP) configuration settings are not enforced correctly.
To exploit the bypasses, an attacker could add script to a webpart, on a SharePoint site, that only a SharePoint site administrator could normally add, and then use the webpart in a cross-site scripting attack in the context of a user visiting the SharePoint site. The bypasses could allow the attacker to read unauthorized content, and perform actions on the SharePoint site as the user, such as change permissions, delete content, and inject malicious content into the user’s browser. The update addresses the bypasses by ensuring that ACP configuration settings are enforced correctly.
The following tables contain links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:
Microsoft has not identified any mitigating factors for this vulnerability.
Workarounds
Microsoft has not identified any workarounds for these vulnerabilities.
Microsoft Office ASLR Bypass - CVE-2016-0012
A security feature bypass exists when Microsoft Office fails to use the Address Space Layout Randomization (ASLR) security feature, allowing an attacker to more reliably predict the memory offsets of specific instructions in a given call stack. An attacker who successfully exploited it could bypass the Address Space Layout Randomization (ASLR) security feature, which helps protect users from a broad class of vulnerabilities. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use this ASLR bypass in conjunction with another vulnerability, such as a remote code execution vulnerability, to more reliably run arbitrary code on a target system.
In a web-browsing scenario, successful exploitation of the ASLR bypass requires a user to be logged on and running an affected version of Microsoft Office. The user would then need to browse to a malicious site. Therefore, any systems where a web browser is used frequently, such as workstations or terminal servers, are at the most risk from this ASLR bypass. Servers could be at more risk if administrators allow users to browse and read email on servers. However, best practices strongly discourage allowing this. The update addresses the ASLR bypass by helping to ensure that affected versions of Microsoft Office properly implement the ASLR security feature.
Microsoft received information about this bypass through coordinated bypass disclosure. At the time this security bulletin was originally issued, Microsoft was unaware of any attack attempting to exploit this bypass.
Mitigating Factors
Microsoft has not identified any mitigating factors for this vulnerability.
Workarounds
Microsoft has not identified any workarounds for this vulnerability.
Security Update Deployment
For Security Update Deployment information, see the Microsoft Knowledge Base article referenced in the Executive Summary.
Acknowledgments
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information.
Disclaimer
The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
Revisions
V1.0 (January 12, 2016): Bulletin published.
V1.1 (January 13, 2016): For CVE-2016-0010, clarified that the Preview Pane is an attack vector for this vulnerability.
This module examines how Microsoft Defender for Office 365 extends EOP protection through various tools, including Safe Attachments, Safe Links, spoofed intelligence, spam filtering policies, and the Tenant Allow/Block List.