Delta-Bench: Differential Benchmark for Static Analysis Security Testing Tools

Background: Static analysis security testing (SAST) tools may be evaluated using synthetic micro benchmarks and benchmarks based on real-world software. Aims: The aim of this study is to address the limitations of the existing SAST tool benchmarks: lack of vulnerability realism, uncertain ground truth, and large amount of findings not related to analyzed vulnerability. Method: We propose Delta-Bench - a novel approach for the automatic construction of benchmarks for SAST tools based on differencing vulnerable and fixed versions in Free and Open Source (FOSS) repositories. To test our approach, we used 7 state of the art SAST tools against 70 revisions of four major versions of Apache Tomcat spanning 62 distinct Common Vulnerabilities and Exposures (CVE) fixes and vulnerable files totalling over 100K lines of code as the source of ground truth vulnerabilities. Results: Our experiment allows us to draw interesting conclusions (e.g., tools perform differently due to the selected benchmark). Conclusions: Delta-Bench allows SAST tools to be automatically evaluated on the real-world historical vulnerabilities using only the findings that a tool produced for the analysed vulnerability.