The exponential growth of Internet of Things (IoT) devices has introduced a broad attack surface, making them prime targets for cyber threats. This is my Erasmus+ exchange semester master's thesis in THM, Germany. It conducts a comprehensive security audit of IoT devices using multiple assessment methodologies, including IP-based tools, Bluetooth-based scanners, hardware audit frameworks, and a blockchain testbed. The core objective is to identify security vulnerabilities, misconfigurations, and loopholes by analyzing exposed services, firmware weaknesses, insecure communications, and hardware-level flaws. We systematically gather device information, uncover known vulnerabilities such as CVEs (Common Vulnerabilities and Exposures), and explore potential zero-day vulnerabilities through custom test cases. Exploitation techniques are employed to validate these weaknesses and demonstrate real-world risks. The findings contribute to a deeper understanding of IoT security gaps and inform the development of improved protection mechanisms. We will work on several test cases, which can be found later in this repository.