The current advances in the Internet of Things (IoT) and the solutions being offered by this technology have accounted IoT among the top ten technologies that will transform the global economy by 2030. IoT is a state-of-the-art paradigm that has developed traditional living into a high-tech lifestyle. The current study aims to provide a comprehensive review and analysis of the existing cybersecurity attacks and vulnerabilities in IoT, offering suitable countermeasures with a focus on describing the impact of emerging technologies on IoT devices and protocol layers. The main vulnerabilities across different layers of the IoT reference model are discussed and categorized, and suitable countermeasures (such as separating IT and IoT network traffic, enhancing physical security, implementing encryption and secure messaging protocols, etc.) are suggested. In addition, the hardware, communication, application, web, and cloud vul-nerabilities are introduced, then the corresponding safeguards and protections are presented. Furthermore, Information Assurance (IA) has been deliberately defined and the adoption of the NIST framework and IA model is recommended as a metric to ensure security for IoT solutions considering the five pillars of availability, integrity, authentication, confidentiality, and non -repudiation. Finally, Blockchain technology, known for its use in securing cryptocurrencies, is suggested to facilitate secure data exchange, identification, authentication, and communication for IoT devices by various avenues including ensuring the integrity of sensor data, eliminating the need for intermediaries, reducing costs, and enabling direct addressability of IoT devices.