Vulnerability analysis For evaluating quality of protection of security policies

Evaluation of security policies, specifically access control policies, plays an important part in securing the network by ensuring that policies are correct and consistent. Quality of protection (QoP) of a policy depends on a number of factors. Thus it is desirable to have one unified score based on these factors to judge the quality of the policy and to compare policies. In this context, we present our method of calculating a metric based on a number of factors like the vulnerabilities present in the system, vulnerability history of the services and their exposure to the network, and traffic patterns. We measure the existing vulnerability by combining the severity scores of the vulnerabilities present in the system. We mine the National Vulnerability Database, NVD, provided by NIST, to find the vulnerability history of the services running on the system, and from the frequency and severity of the past vulnerabilities, we measure the historical vulnerability of the policy using a decay factor. In both cases, we take into account the exposure of the service to the network and the traffic volume handled by the service. Finally, we combine these scores into one unified score - the Policy Security Score.