Message Queuing Telemetry Transport (MQTT) is a lightweight, machine-to-machine messaging protocol created in 1999 as a way for low-bandwidth communication such as satellite. A security researcher found 65,000 open MQTT servers worldwide on the public Internet wide open to attack with no authentication nor encrypted communication. Later this month at Black Hat USA in Las Vegas, researcher Lucas Lundgren plans to demonstrate how an attacker could snoop on and even sabotage power plant equipment, ATM machines, and other connected devices.”]
Source: https://www.darkreading.com/cloud/iot-devices-plagued-by-lesser-known-security-hole