Modeling Local Exploit Hazard - A Bayesian Framework for Quantifying Exploit Risk and Operational Efficiency

This paper presents a local exploit hazard model: a Bayesian framework that converts the global probabilities produced by an exploit likelihood model (ELM), such as the Exploit Prediction Scoring System (EPSS), into a daily exploit hazard rate for an organization's own assets. The model measures the exploit-prevention effectiveness of deployed controls as a probability distribution. That distribution is seeded from a subject-matter-expert opinion pool and updated through Beta-Binomial inference from telemetry, breach-and-attack simulation, or penetration testing, then applied to ELM scores by attack-vector alignment. The resulting per-vulnerability exploitation likelihoods are converted into hazard rates using standard survival-analysis techniques, supporting both a constant exponential hazard and a Weibull hazard whose shape parameter, calibrated from Known Exploited Vulnerabilities catalog timing, captures the empirical decay of exploitation risk as a vulnerability ages. Because hazards are additive under independence, per-vulnerability rates aggregate by summation up to host, network, business unit, and organization. Candidate remediation actions are simulated and ranked by projected hazard reduction, giving defenders a defensible, quantitative basis for prioritization under fixed capacity. Future work includes extensions for incident likelihood and financial loss modeling.