Analysing vulnerability reproducibility for Firefox browser.

Fixing some security failures are difficult because they cannot be easily reproduced. To address Hardly Reproducible Vulnerabilities (HRVs), security experts spend a significant amount of time, effort, and budget. Sometimes they do not succeed in the reproduction step and ignore some security failures. The exploitation of a vulnerability due to its irreproducibility may cause severe consequences. An efficient solution is to explore the behaviour of both hardly and easily reproducible security issues at the code level. We use linear regression techniques to build models based on the classical software complexity metrics and a set of attributes related to the environment of the system. The results show that the considered metrics and the vulnerability types do not have significant linear correlations with each other. Also, predicting the HRV-prone parts of large systems is a great help for security experts to focus their effort on the top-ranked vulnerable files. After identifying the suitable indicators based on linear regression, different machine learning techniques such as Random Forest, Logistic Regression, C4.5 Decision Tree, and Naive Bayes are employed to build HRV prediction models. The Random Forest technique achieves the precision of 82% and recall of 84% to classify vulnerable files into HRV-prone or non HRV-prone files. We believe that the results encourage the use of software metrics for vulnerability prediction in some projects.