This thesis introduces CAPutt, a modular, over‑the‑air black‑box fuzzing framework for Bluetooth Classic tailored to automotive systems where source code and instrumentation are unavailable. CAPutt combines two complementary engines: a Service Fuzzer that perturbs higher‑layer payloads over valid L2CAP channels, and a stateful L2CAP Fuzzer that mutates structure‑aware fields to drive negotiated and transitional states. The framework emphasizes automation and resilience through online mutation aligned to negotiated parameters, HCI‑level capture and logging, a replay module for minimal triggering sequences, and robust recovery from disconnects. We evaluate CAPutt in a controlled lab that mirrors MQB/MEB benches, targeting Volkswagen’s ICAS3 (BlueSDK) with BlueZ on Raspberry Pi as a baseline.