M-Bus, short for Meter-Bus, is a communication protocol used to read data from utility meters and related building equipment such as heat, water, gas, and energy meters. It is designed for remote metering, so a gateway can collect usage data from many devices and forward it to billing or monitoring systems.
In cyber security, M-Bus matters because it often sits between field devices and IP-connected management tools. That makes the gateway and its management interface part of the attack surface. If an attacker reaches the gateway through weak access controls, poor network segmentation, or exposed remote administration, they may be able to disrupt meter reporting, alter configuration, or interfere with billing data. Defenders reduce this risk by inventorying M-Bus assets, patching gateways, restricting remote access, and isolating metering networks from general-purpose systems.