Modern transportation infrastructure is starting to include more and more intelligent transportation systems (ITSs), which provide towns and cities safe, effective transportation options. However, ITSs’ dependence on networked technology also raises the possibility of security flaws that hackers may take advantage of. This chapter examines the several kinds of cyber security assaults that may be directed at Information and Communication Technology Systems (ICTSs), including malware, phishing, remote access, denial of service (DoS), physical, insider threat, and social engineering attacks. It also covers the possible fallout from these attacks, which can include everything from bodily harm to fatalities to service interruptions. Intelligent transportation systems (ITS) are intricate, time-sensitive systems where the availability of cyber security directly affects both the effectiveness of transportation services and the physical safety of road users. While ITS standards are being developed, neither the formation of a security strategy nor the implementation of a complete standard have yet to occur. It is necessary to carefully analyze and evaluate the compatibility between the different ITS standards and the interactions with the outside world (Smart Cities, IoT). Intelligent Transportation Systems (ITS) have been created and implemented during the past few decades with the goal of increasing productivity, promoting sustainable transportation development, lowering environmental impact, and improving safety and mobility. ITS blends cutting-edge technology with the traditional realm of transportation infrastructure, using advancements in information systems, communication, sensors, controllers, and sophisticated mathematical techniques. For a rookie researcher, it might be challenging to get a comprehensive view of the entire system because this is an inter-disciplinary subject of study.