Bluetooth is a widely used communication technology, especially under the scenarios of mobile computing and Internet of Things. Once paired with a host device, a Bluetooth device then can exchange commands and data, such as voice, keyboard/mouse inputs, network, blood pressure data, and so on, with the host. Due to the sensitivity of such data and commands, some security measures have already been built into the Bluetooth protocol, like authentication, encryption, authorization, etc. The newly discovered vulnerabilities can lead to severe attacks on user's privacy. To demonstrate the potential security implications of these vulnerabilities, we devise several concrete