With emerging of the Internet, the way we communicate with each other has fundamentally revolutionized. The second development wave of the Internet is not about people, but will be about smart connected devices. Although more than a decade passes from the proposing of "Internet of Things" concept, the deployment of this concept has been done slowly for various reasons such as lack of required technologies development and security challenges. We must spend more time to understand the security challenges and available solutions, when we speak about smarter environments and technologies such as IoT. In this paper, we attempt to analysis existent threats and vulnerabilities in the area of security and privacy of Internet of Things using a systematic approach, while presenting a survey of the solutions proposed in the literature. Finally, research opportunities of this area will be discussed.