Exam CS0-002 topic 1 question 341 discussion

"Modbus is that it is not designed to be run on open networks, it was intended to be used on dedicated lines, such as a serial connection, or a closed network.... The Modbus protocol itself contains no security whatsoever. If you can communicate directly with a Modbus server or client you can issue commands." -this is a vulnerability with Modbus. "Modbus is an industrial control system (ICS) network protocol that is used for communication between devices such as sensors, controllers, actuators, and monitors. Modbus has no inherent security functions on TCP port 502, which is the default port for Modbus TCP/IP communication. Modbus does not provide any encryption, authentication, or integrity protection for the data transmitted over the network, making it vulnerable to various attacks such as replay, modification, spoofing, or denial-of-service."