Since the beginning of the century, Cyber-Physical Systems (CPS) started to be adopted by many fields, such as industry, medicine, driving, and even everyday life with the Internet Of Things. However, the widespread usage of CPS in a vastly different scenario led to a security issue. Furthermore, due to the nature of CPS (use cases, vast topologies, and cost of the systems), it is impossible to build testbeds and test systems in most cases. In this context, the thesis aims to use virtual network simulation tools to simu- late a precise kind of CPS: SCADA system. In particular, MiniCPS, a framework built on top of Mininet, and GNS3 have been used to simulate a water purification process called Secure Water Treatment.