An issue was discovered on COROS PACE 3 devices through 3.0808.0. The BLE implementation of the COROS smartwatch does not support LE Secure Connections and instead enforces BLE Legacy Pairing. In BLE Legacy Pairing, the Short-Term Key (STK) can be easily guessed. This requires knowledge of the Temporary Key (TK), which, in the case of the COROS Pace 3, is set to 0 due to the Just Works pairing method. An attacker within Bluetooth range can therefore perform sniffing attacks, allowing eavesdropping on the communication.