Biblio

Nowadays, the domain of Information System (IS) security is closely related to that of Risk Management (RM). As an immediate consequence, talking about and tackling the security of IS imply the implementation of a set of mechanisms that aim to reduce or eliminate the risk of IS degradations. Also, the high cadence of IS evolution requires careful consideration of corresponding measures to prevent or mitigate security risks that may cause the degradation of these systems. From this perspective, an access control service is subjected to a number of rules established to ensure the integrity and confidentiality of the handled data. During their lifecycle, the use or manipulation of Access Control Policies (ACP) is accompanied with several defects that are made intentionally or not. For many years, these defects have been the subject of numerous studies either for their detection or for the analysis of the risks incurred by IS to their recurrence and complexity. In our research works, we focus on the analysis and risk assessment of noncompliance anomalies in concrete instances of access control policies. We complete our analysis by studying and assessing the risks associated with the correlation that may exist between different anomalies. Indeed, taking into account possible correlations can make a significant contribution to the reliability of IS. Identifying correlation links between anomalies in concrete instances of ACP contributes in discovering or detecting new scenarios of alterations and attacks. Therefore, once done, this study mainly contributes in the improvement of our risk assessment model.

Legacy work on correcting firewall anomalies operate with the premise of creating totally disjunctive rules. Unfortunately, such solutions are impractical from implementation point of view as they lead to an explosion of the number of firewall rules. In a related previous work, we proposed a new approach for performing assisted corrective actions, which in contrast to the-state-of-the-art family of radically disjunctive approaches, does not lead to a prohibitive increase of the configuration size. In this sense, we allow relaxation in the correction process by clearly distinguishing between constructive anomalies that can be tolerated and destructive anomalies that should be systematically fixed. However, a main disadvantage of the latter approach was its dependency on the guided input from the administrator which controversially introduces a new risk for human errors. In order to circumvent the latter disadvantage, we present in this paper a Firewall Policy Query Engine (FPQE) that renders the whole process of anomaly resolution a fully automated one and which does not require any human intervention. In this sense, instead of prompting the administrator for inserting the proper order corrective actions, FPQE executes those queries against a high level firewall policy. We have implemented the FPQE and the first results of integrating it with our legacy anomaly resolver are promising.