Evaluating Method of Security Threat Based on Attacking-Path Graph Model

In order to solve the problems of evaluating system security threat in the complex system, a novel system security threat model based on the attacking-tree graph is proposed in this paper. In this model, an evaluating standard of the feasibility and harmful level of the vulnerability exploitation is given. Then an attacking-tree graph of the target system is constructed based on the relationship among exploitations of vulnerabilities. Using methods in the graph theory and probability theory, a thorough analysis of system security threats is also given. The impact of all kind of threats on the system security can be got from this model. So, several difficult problems in the evaluations of attacking-path threats, vulnerability threats are solved.