A method, apparatus and computer-readable medium for testing a target device. A fuzzer and a monitor are connected to the target device via a tactical bus. The fuzzer records messages sent from a source device to the target device over the tactical bus, creates a first fuzzed message having a data structure of the recorded message, and sends the first fuzzed message to the target device over the tactical bus. A fuzzer monitor monitors the target device for an anomalous response to the first fuzzed message, and determines a vulnerability of the target device from the response to the first fuzzed message.