CNC machines are largely used in production plants and constitute a critical asset for organizations globally. The strong push dictated by the Industry 4.0 paradigm led to the introduction of technologies for the wide connectivity of industrial equipment, including CNCs. As a result, modern CNCs resemble more fully-fledged systems rather than mechanical machines, offering numerous networking services for smart connectivity. Given this shift into a more complex and software-dependable ecosystem, these machines are left more easily exposed to potential threats. Our work explored the risks associated with the strong technological development observed in the domain of numerical controls. We conducted an empirical evaluation of four representative controller manufacturers, by analyzing the technologies introduced to satisfy the needs of the Industry 4.0 paradigm, and conducting a series of practical attacks against real-world CNC installations.Our findings revealed that malicious users could abuse such technologies to conduct attacks like denial-of-service, damage, hijacking or theft. We reported our findings to the affected vendors and proposed mitigations. This talk wants to be an opportunity to raise awareness in a domain in which, unfortunately, security is not yet considered an important driver.