A number of security vulnerabilities have been reported in the Windows, and Linux operating systems. Both the developers, and users of operating systems have to utilize significant resources to evaluate, and mitigate the risk posed by these vulnerabilities. Vulnerabilities are discovered throughout the life of a software system by both the developers, and external testers. Vulnerability discovery models are needed that describe the vulnerability discovery process for determining readiness for release, future resource allocation for patch development, and evaluating the risk of vulnerability exploitation. Here, we analytically describe six models that have been recently proposed, and evaluate those using actual data for four major operating systems. The applicability of the proposed models, and the significance of the parameters involved are examined. The results show that some of the models tend to capture the discovery process better than others.

The Internet of Things (IoT) is a vital component of many future industries. By intelligent integration of sensors, wireless communications, computing techniques, and data analytics, IoT can increase productivity and efficiency of industries. Reliability of data transmission is key to realize several applications offered by IoT. In this paper, we present an overview of future IoT applications, and their major communication requirements. We provide a brief survey of recent work in four major areas of reliable IoT including resource allocation, latency management, security, and reliability metrics. Finally, we highlight some of the important challenges for reliable IoT related to machine learning techniques, 6G communications and blockchain based security that need further investigation and discuss related future directions.