This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow remote code execution in a host context if a specially crafted application is run by an authenticated and privileged user on a guest virtual machine hosted by Hyper-V. An attacker must have valid logon credentials for a guest virtual machine to exploit this vulnerability.
This security update is rated Critical for Windows Hyper-V on Windows Server 2008, Windows Server 2008 R2, Windows 8 and Windows Server 2012, and Windows 8.1 and Windows Server 2012 R2. For more information, see the Affected Software section.
The security update addresses the vulnerabilities by correcting how Hyper-V initializes system data structures in guest virtual machines. For more information about the vulnerabilities, see the Vulnerability Information section.