An evaluation device comprising: a test data transmitter (21, 22) configured to transmit test data to a controller of a vehicle-mounted device being a meter device configured to indicate information relating to a vehicle and including an operating section and the controller configured to control the operating section including a first indicator being an image displaying device, and a second indicator being an indicating light or an analog instrument, the test data executing normal operation of the operating section; a fuzzing data transmitter configured to transmit fuzzing data to the controller, the fuzzing data being improper data differing from the test data executing the normal operation; an output status variation detector configured to detect variation from an output status in the normal operation upon transmission of the fuzzing data to the controller by the fuzzing data transmitter with the controller executing the normal operation of the operating section based on the test data transmitted by the test data transmitter (21, 22), the output status in the normal operation being a visually recognizable output status in the normal operation, wherein the output status variation detector includes: - an image signal variation detector configured to detect variation from the output status in the normal operation based on variation of an image signal displaying the output status in the normal operation on the first indicator, the image signal being transmitted from the controller to the first indicator; and - a taken image variation detector configured to detect variation from the output status in the normal operation based on variation of a taken image obtained by imaging the output status in the normal operation of the second indicator by an imager; and an evaluator configured to evaluate vulnerability of the controller based on the variation from the output status in the normal operation, the variation being detected by the output status variation detector. a test data transmitter (21, 22) configured to transmit test data to a controller of a vehicle-mounted device being a meter device configured to indicate information relating to a vehicle and including an operating section and the controller configured to control the operating section including a first indicator being an image displaying device, and a second indicator being an indicating light or an analog instrument, the test data executing normal operation of the operating section; a fuzzing data transmitter configured to transmit fuzzing data to the controller, the fuzzing data being improper data differing from the test data executing the normal operation; an output status variation detector configured to detect variation from an output status in the normal operation upon transmission of the fuzzing data to the controller by the fuzzing data transmitter with the controller executing the normal operation of the operating section based on the test data transmitted by the test data transmitter (21, 22), the output status in the normal operation being a visually recognizable output status in the normal operation, wherein the output status variation detector includes: - an image signal variation detector configured to detect variation from the output status in the normal operation based on variation of an image signal displaying the output status in the normal operation on the first indicator, the image signal being transmitted from the controller to the first indicator; and - a taken image variation detector configured to detect variation from the output status in the normal operation based on variation of a taken image obtained by imaging the output status in the normal operation of the second indicator by an imager; and - an image signal variation detector configured to detect variation from the output status in the normal operation based on variation of an image signal displaying the output status in the normal operation on the first indicator, the image signal being transmitted from the controller to the first indicator; and - a taken image variation detector configured to detect variation from the output status in the normal operation based on variation of a taken image obtained by imaging the output status in the normal operation of the second indicator by an imager; and an evaluator configured to evaluate vulnerability of the controller based on the variation from the output status in the normal operation, the variation being detected by the output status variation detector.