Trust and reputation systems play important roles in supplier selection, a topic that has been widely investigated from a business and operation point of view. However, we still lack of effective studies on supplier selection with security as the optimal target, which is a very important factor for Information and Communication Technology (ICT) systems. In response, this paper outlines a method that enables people to evaluate the relative and objective trustworthiness of the alternative suppliers. Our analysis is based solely on the original data of the vulnerabilities publicly available from OSVDB and NVD, which are impossible to tamper with. They are then interpreted by an approach that combines the Analytic Hierarchy Process (AHP) and objective analysis that enables the inference of relative trust valuations based on different evaluation indexes. A case study of five well known vendors is demonstrated with qualitative comparison based on visualization of data.