11 Common Bluetooth Attack Methods Explained

In modern lifestyles, the application of Bluetooth technology has become very widespread. It is a short-range communication open standard that uses embedded chips to achieve wireless connections over short distances. It features low cost, low power consumption, small module size, and ease of integration, making it very suitable for application in new types of Internet of Things (IoT) mobile devices.

However, like other wireless technologies, Bluetooth communication is also very susceptible to attacks, as it requires the use of various chipsets, operating systems, and physical device configurations. There are numerous different security programming interfaces and default settings, and this complexity leads to unavoidable security vulnerabilities in Bluetooth devices.

The application of Bluetooth technology is rapidly developing, which means more attack surfaces will arise. This article will introduce the 11 most common Bluetooth attack methods and their characteristics from the perspective of enhancing security awareness in Bluetooth applications:

The Bluesnarf attack is one of the most popular types of Bluetooth attacks today. It exploits the Bluetooth Object Exchange (OBEX) file transfer protocol, allowing the attacker to pair with the victim’s Bluetooth device. This attack forces the establishment of a transmission channel to access the target Bluetooth device, allowing access to data on the device, including the International Mobile Equipment Identity (IMEI). The IMEI is a unique identifier for each device, and the attacker may use it to route normal access requests from the user’s device to the attacker’s device.

This attack method is similar to the Bluesnarf attack, with the main difference being the method used by the attacker to access the file system. If a file transfer protocol (FTP) server runs on OBEX, OBEX push services can be used to achieve access connections without pairing with the device. In this way, the attacker can access, view, and modify files on the target device without authentication and matching requests.

This attack method refers to the attacker using data provided by Bluetooth technology to obtain information about the device’s brand, model, etc. The first three digits of the Bluetooth device’s MAC address provide information about the device and its manufacturer. In addition, supported applications, open ports, etc., are also available. Through this information, the attacker can learn the brand and model of the target device, and even the currently running Bluetooth software version. Through BluePrinting attacks, attackers can gain detailed information about the target device’s operating system, thereby narrowing down the attack vector.

“Hello Moto” is a classic slogan from Motorola phones, which many people remember. The HelloMoto attack exploits a trust management vulnerability in some Motorola phone devices. Initially, the attacker uses OBEX push services to send a vCard (a virtual business card with contact information), then the attacker interrupts this process and creates a failed task. After that, the attacker can access content such as headset profiles without authentication.

This attack requires some social engineering techniques, where the principle is to first establish a secure connection with the victim. This can be achieved through virtual work cards or file transfers. Once the victim adds the attacker to the trusted device list, the attacker can delete the connection key without interrupting the connection. After the clearance is complete, the attacker can maintain a long-term connection to the victim’s Bluetooth device and record their daily work information. Meanwhile, the attacker will also request to re-encrypt their current connection, allowing the attack device to enter the victim’s trust list without authentication, thus gaining access to the target device.

In this attack scenario, the attacker must know the address (BD_ADDR) paired with the Bluetooth device, which is a unique identifier assigned by the manufacturer to each device. The attacker will replace their address with the address of the victim’s connected device and connect to the victim. Since the attacker does not have the connection key, the victim’s device will not return any connection key when trying to connect. In some cases, this may cause the victim’s device to clear the connection key and re-enter pairing mode. At this point, the attacker can enter pairing mode and read key changes, and they will also participate in the key exchange, allowing them to perform a man-in-the-middle (MITM) attack.

This attack takes advantage of the ability of a master device to connect multiple devices to create a Bluetooth extended scatternet (Scatternet), with the aim of disconnecting the Pictonet connection to the Scatternet device and attempting to disrupt the network. The attacker will replace their address with the address of the device connected to the Pictonet and establish a connection with the host device, which will cause the Pictonet connection to be interrupted.

Authentication applies to all users requesting access to Bluetooth devices. However, anyone connected to the target Bluetooth device can also use other unauthorized access services. In this attack, the attacker will attempt to connect to unauthorized services running on the Bluetooth device and use these services for their malicious purposes.

BlueSmack is a denial of service (DoS) attack that can be created using the Linux BlueZ Bluetooth layer. Essentially, the data packets sent by cybercriminals overwhelm the target device. This is achieved through the Logical Link Control and Adaptation Protocol (L2CAP) layer, which aims to check connections and measure round-trip times. With specific attack tools, the attacker can change the size of the sent packets, causing the attacked device to become paralyzed.

The BlueBorne attack primarily exploits vulnerabilities in the Bluetooth stack to connect to devices without the owner’s knowledge and gain maximum command execution permissions within the device. This allows the attacker to perform all operations on the device, such as listening, modifying data, reading, tracking, etc. The problem arises because some Bluetooth chips can connect to the main chip without security checks and accurate authorization.

In this attack, the attacker uses the default PIN code provided by the car’s Bluetooth device to simulate a phone connection to the vehicle system. Once connected, they can control various Bluetooth application systems in the vehicle and obtain relevant information. Although this situation is currently rare, with the rapid application of Internet of Vehicles technology, its security threats will become increasingly alarming.

As IoT technology rapidly advances in manufacturing, agriculture, and home devices, the development prospects of Bluetooth applications cannot be underestimated. However, it is also essential to pay special attention to the security challenges involved. Therefore, the industry generally expects that future Bluetooth application standard designs can further increase necessary security protection strategies. Meanwhile, users’ security awareness should also be enhanced as quickly as possible when using Bluetooth devices for connections and transmissions, striving to use secure and reliable connection modes, and promptly turning off Bluetooth devices after use.