A comprehensive review of cybersecurity vulnerabilities, threats, and solutions for the Internet of Things at the network-cum-application layer

The proliferation of smart homes, smart logistics, and other technologies has expedited the expansion of Internet-of-Things (IoT) devices. This expansion has heightened the complexity of associated security challenges. Despite extensive research on IoT security, several studies fail to provide a comprehensive examination of both the network and application layers. This is particularly applicable to real-time and mission-critical settings. This review addresses that deficiency by offering a systematic review of IoT across five tiers. It concentrates on the application layer, categorizing it into three domains: real-time control systems, scientific decision-making systems, and query/scan search systems. The study examines vulnerabilities, attack vectors, and security measures in real-time control and query/scan systems. It examines how emerging technologies such as artificial intelligence (AI), Software Defined Networking (SDN), and fog/edge computing can enhance security via improved context awareness and access management. The study ultimately presents recommendations and suggests enhancements to foster trust, scalability, and enhanced security in contemporary IoT systems.