Attribute Repair for Threat Prevention

We propose a model-based procedure for preventing security
threats using formal models. We encode system models and threats as
satisfiability modulo theory (SMT) formulas. This model allows us to ask
security questions as satisfiability queries. We formulate threat preven-
tion as an optimization problem over the same formulas. The outcome
of our threat prevention procedure is a suggestion of model attribute
repair that eliminates threats. We implement our approach using the
state-of-the-art Z3 SMT solver and interface it with the threat analysis
tool THREATGET. We demonstrate the value of our procedure in two
case studies from automotive and smart home domains.