Cisco Web Security Appliance is prone to an unauthorized-access vulnerability. Attackers can exploit this issue to gain unauthorized access and perform unauthorized actions. This may aid in further attacks. This issue is being tracked by Cisco Bug ID CSCvp51493.
Block external access at the network boundary, unless external parties require service.
If global access isn't needed, block access at the network perimeter to computers hosting the vulnerable device.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity such as unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.
Updates are available. Please see the references or vendor advisory for more information.