Less is More: Supporting Developers in Vulnerability Detection during Code Review
This addresses the issue of security vulnerabilities being overlooked in code reviews for software developers, though it is incremental as it builds on prior research about mental attitudes.
The study tackled the problem of developers missing vulnerabilities during code review by investigating if explicitly asking them to focus on security improves detection, finding that it increases the probability of vulnerability detection eight times, while a security checklist did not significantly enhance outcomes further.
Reviewing source code from a security perspective has proven to be a difficult task. Indeed, previous research has shown that developers often miss even popular and easy-to-detect vulnerabilities during code review. Initial evidence suggests that a significant cause may lie in the reviewers' mental attitude and common practices. In this study, we investigate whether and how explicitly asking developers to focus on security during a code review affects the detection of vulnerabilities. Furthermore, we evaluate the effect of providing a security checklist to guide the security review. To this aim, we conduct an online experiment with 150 participants, of which 71% report to have three or more years of professional development experience. Our results show that simply asking reviewers to focus on security during the code review increases eight times the probability of vulnerability detection. The presence of a security checklist does not significantly improve the outcome further, even when the checklist is tailored to the change under review and the existing vulnerabilities in the change. These results provide evidence supporting the mental attitude hypothesis and call for further work on security checklists' effectiveness and design. Data and materials: https://doi.org/10.5281/zenodo.6026291