Static Analysis of Format String Vulnerabilities

This paper presents a novel approach, based on static analysis, to detect format string vulnerabilities in C programs. Format string vulnerability is viewed as a finite state safety property. The analysis is expressed as a system of constraint describing how the safety state at one program point is related to the state at adjacent program points. Our analysis is inter-procedurally flow sensitive and intra-procedurally path sensitive. To avoid state space explosion in inter-procedural analysis, we use procedural summary instead of analyzing the called function holistically. The experimental results show that this method can effectively locate format string vulnerabilities in C programs. In comparison with other static approaches, ours can greatly reduce false positive.