Microsoft Windows Hyper-V bypass security restriction Vulnerability

A security feature bypass vulnerability exists in Windows Hyper-V when access control list (ACL) configuration settings are not applied correctly. To exploit the vulnerability, an attacker could run a specially crafted application that could cause Hyper-V to allow unintended network traffic. Customers who have not enabled the Hyper-V role are not affected. The security update addresses the vulnerability by correcting how Hyper-V applies ACL configuration settings.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was originally issued Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.