Microsoft Lync for Mac Certificate Validation Vulnerability

A security feature bypass exists when the Lync for Mac 2011 client fails to properly validate certificates. An attacker who successfully exploited this vulnerability could tamper with trusted communications between the server and target client. To exploit the vulnerability, an attacker would need to intercept and tamper with network traffic. The security update addresses the vulnerability by correcting how the Lync for Mac 2011 client validates certificates.