A method and device for handling an anomaly at a unit. The device is integrated into the unit. A variable is detected for handling attacks on the unit that defines an operation of the unit. A piece of information is determined depending on the variable that characterizes surroundings in which the unit is operated. It is checked depending on a comparison of the piece of information about the surroundings to a piece information about the setpoint surroundings for the operation of the unit, whether or not an anomaly is present in the operation of the unit. The unit is operated in a first operating mode having a first functional range, if no anomaly is detected. The unit is operated in a second operating mode having a second functional range, which is reduced or changed with regard to the first functional range, if an anomaly is detected.