Forecasting the risk of software choices: A model to foretell security vulnerabilities from library dependencies and source code evolution

Abstract: Software security mainly studies vulnerability detection: is my code vulnerable today? This hinders risk estimation, so new approaches are emerging to forecast the occurrence of future vulnerabilities. While useful, these approaches are coarse-grained and hard to employ for project-specific technical decisions. We introduce a model capable of vulnerability forecasting at library level. Formalising source-code evolution in time together with library dependency, our model can estimate the probability that a software project faces a CVE disclosure in a future time window. Our approach is white-box and lightweight, which we demonstrate via experiments involving 1255 CVEs and 768 Java libraries, made public as an open-source artifact. Besides probabilities estimation, e.g. to plan software updates, this formal model can be used to detect security-sensitive points in a project, or measure the health of a development ecosystem.