Security Metrics for Risk-Aware Automated Policy Management

The factors on which security depends are of a dynamic nature. They include emergence of new vulnerabilities and threats, policy structure, and network traffic. Therefore, evaluating security from both the service and policy perspective can allow the management system to make decisions regarding how a system should be changed to enhance security as par the management objective. Such decision making includes choosing between alternative security architectures, designing security countermeasures, and systematically modifying security configurations to improve security. Moreover, this evaluation must be done dynamically to handle real-time changes to the network threat. This chapter provides a security metric framework that quantifies objectively the most significant security risk factors, which include the historical trend of vulnerabilities of the remotely accessible services, prediction of potential vulnerabilities in the near future for these services and their estimated severity, existing vulnerabilities, unused address space, and finally, propagation of an attack within the network. These factors cover both the service aspect and the network aspect of risk toward a system. This framework is implemented as a user-friendly tool called Risk-based prOactive seCurity cOnfiguration maNAger (ROCONA) and shows how this tool simplifies security configuration management of services and policies in a system using risk measurement and mitigation. This chapter also combines all the components into one single metric and present validation experiments using real-life vulnerability data from the National Vulnerability Database (NVD) and shows a comparison with existing risk measurement tools.