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 about the vulnerabilities, see the Affected Software and Vulnerability Severity Ratings section.
The security update addresses the vulnerabilities by correcting how:
Office handles objects in memory
Certain functions handle objects in memory
Windows validates input before loading libraries
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 June bulletin summary.
*The Updates Replaced column shows only the latest update in a chain of superseded updates.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).
*The Updates Replaced column shows only the latest update in a chain of superseded updates.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).
Update FAQ
Do these updates contain any additional security-related changes to functionality?
Yes. In addition to the security updates that address the vulnerabilities described in this bulletin, Microsoft is releasing a security enhancement for Microsoft OneNote. After installing the updates listed in the following table, when users click a hyperlink in OneNote, they will be prompted to confirm whether they want to navigate to the selected URL.
I have Microsoft Word 2010 installed. Why am I not being offered the 3115198 update?
The 3115198 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. Furthermore, 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 more information on this behavior and recommended actions, see Microsoft Knowledge Base Article 830335. For a list of Microsoft Office products that an update may apply to, refer to the Microsoft Knowledge Base Article associated with the specific update.
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 the 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 the 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.
Note that where the severity is indicated as Critical in the Affected Software and Vulnerability Severity Ratings table, the Preview Pane is an attack vector for CVE-2016-0025. The security update addresses the vulnerability by correcting how Office handles objects in memory.
The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:
Microsoft has not identified any mitigating factors for these vulnerabilities.
Workarounds
Microsoft has not identified any workarounds for this vulnerability.
Microsoft Office Information Disclosure Vulnerability - CVE-2016-3234
An information disclosure vulnerability exists when Microsoft Office improperly discloses the contents of its memory. An attacker who exploited the vulnerability could use the information to compromise the user’s computer or data. To exploit the vulnerability, an attacker could craft a special document file, and then convince the victim to open it. An attacker must know the memory address location where the object was created. The update addresses the vulnerability by changing the way certain functions handle objects in memory.
The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:
Vulnerability title
CVE number
Publicly disclosed
Exploited
Microsoft Office Information Disclosure Vulnerability
Microsoft has not identified any mitigating factors for this vulnerability.
Workarounds
The following workaround may be helpful in your situation:
Workaround for CVE-2016-3234
Use Microsoft Office File Block policy to prevent Office from opening RTF documents from unknown or untrusted sources Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
For Office 2007
Run regedit.exe as Administrator and navigate to the following subkey:
Set the RtfFiles DWORD value to 1. Note To use 'FileOpenBlock' with Office 2007, all of the latest Office 2007 security updates as of May 2007 must be applied.
For Office 2010
Run regedit.exe as Administrator and navigate to the following subkey:
Impact of Workaround. Users who have configured the File Block policy and have not configured a special “exempt directory” as discussed in Microsoft Knowledge Base Article 922849 will be unable to open documents saved in the RTF format.
How to undo the workaround
For Office 2007
Run regedit.exe as Administrator and navigate to the following subkey:
Leave the OpenInProtectedView DWORD value set to 0.
Prevent Word from loading RTF files
Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Interactive managed script method
For Word 2007
Click Start, click Run, in the Open box, type regedit, and then click OK.
Locate and then click the following registry subkey:
Run the above registry script created in step 1 on the target machine with the following command from an administrator command prompt: Regedit / s Disable_RTF_In_Word.reg
Note RTF files will not be readable by Word.
Microsoft Office OLE DLL Side Loading Vulnerability - CVE-2016-3235
A remote code execution vulnerability exists when Windows improperly validates input before loading libraries. An attacker who successfully exploited the vulnerability could take control of an 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 vulnerability, an attacker would need access to the local system and the ability to execute a specially crafted application on the system. The security update addresses the vulnerability by correcting how Windows validates input before loading libraries.
The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:
Vulnerability title
CVE number
Publicly disclosed
Exploited
Microsoft Office OLE DLL Side Loading Vulnerability
Microsoft has not identified any mitigating factors for these vulnerabilities.
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.
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.