Cisco fixes maximum severity MSO auth bypass vulnerability By 04:03 PM Cisco has addressed a maximum severity authentication bypass vulnerability found in the API endpoint of the Cisco ACI Multi-Site Orchestrator (MSO) installed on the Application Services Engine. Cisco ACI MSO is an intersite network and policy orchestration solution that helps admins monitor the health of their organizations' interconnected sites across multiple data centers. Impacts only MSO 3.0 releases "A vulnerability in an API endpoint of Cisco ACI Multi-Site Orchestrator (MSO) installed on the Application Services Engine could allow an unauthenticated, remote attacker to bypass authentication on an affected device," Cisco explained.