Vulnerability Assessment of Web Services with Model-Based Mutation Testing

We present a model-based mutation testing approach, for evaluating the authentication and authorization of web services in a multi-user context. Model of a web service and its security requirements are designed using UPPAAL Timed Automata. The model is mutated to create invalid behavior which is used for test generation to reveal faults in the system under test. The approach is supported by a model-based mutation testing tool, µUTA, that automatically generates mutants, selects a collection of suitable mutants for testing and generates test cases from them. We modify a previously defined mutation operator and introduce three new operators for additional mutants. We define criteria for the mutation-selection and demonstrate the approach on a blog web service. Results show that the approach can discover authorization faults that were not detected by traditional methods.