Microsoft Office Remote Code Execution Vulnerability

Security Vulnerability

Released: Jun 13, 2017

Last updated: Jul 5, 2017

Assigning CNA
Microsoft
CVE.org link
CVE-2017-8509

Executive Summary

A remote code execution vulnerability exists in Microsoft Office software when it fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could use a specially crafted file to perform actions in the security context of the current user. For example, the file could then take actions on behalf of the logged-on user with the same permissions as the current user.

To exploit the vulnerability, a user must open a specially crafted file with an affected version of Microsoft Office software. In an email attack scenario, an attacker could exploit the vulnerability 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 vulnerability. However, an attacker would have no way to force the user to visit the website. Instead, an attacker would have to convince the user to click a link, typically by way of an enticement in an email or Instant Messenger message, and then convince the user to open the specially crafted file.

The security update addresses the vulnerability by correcting how Microsoft Office handles files in memory.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed
No
Exploited
No
Exploitability assessment
Exploitation Less Likely

FAQ

  1. The affected software table contains the link to the SharePoint Server 2013 cumulative update, KB 3203430, which includes all of the required SharePoint Server 2013 updates for CVE-2017-8509. As an alternative to installing the cumulative update, you may install the individual security updates from the following links. You must install all packages applicable to your environment to be protected from the vulnerability described in CVE-2017-8509.

    3203384 3203388 3203390 3203397 3203385 3172445

  2. Microsoft has also released an update for Microsoft Office for Mac 2011 and Microsoft Office for Mac 2016 as a defense-in-depth measure.

  3. I have Microsoft Word 2010 installed. Why am I not being offered the KB3203463 update? The KB3203463 update only applies to systems running specific configurations of Microsoft Office 2010. Other systems will not be offered the update.

Acknowledgements

  • Haifei Li of the McAfee Security Team
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

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

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