Responding to Anomalous Database Requests

Organizations have recently shown increased interest in database activity monitoring and anomaly detection techniques to safeguard their internal databases. Once an anomaly is detected, a response from the database is needed to contain the effects of the anomaly. However, the problem of issuing an appropriate response to a detected database anomaly has received little attention so far. In this paper, we propose a framework and policy language for issuing a response to a database anomaly based on the characteristics of the anomaly. We also propose a novel approach to dynamically change the state of the access control system in order to contain the damage that may be caused by the anomalous request. We have implemented our mechanisms in PostgreSQL and in the paper we discuss relevant implementation issues. We have also carried out an experimental evaluation to assess the performance overhead introduced by our response mechanism. The experimental results show that the techniques are very efficient.