This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user opens a specially crafted Microsoft Office file containing a malicious embedded ClickOnce application. An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. 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.
This security update is rated Important for all supported releases of Microsoft Windows. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update addresses the vulnerability by changing the way that Windows Packager checks for unsafe files. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.
Recommendation. The majority of customers have automatic updating enabled and 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 and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.