Discoverable mode definition
Discoverable mode is a state in which a Bluetooth device becomes visible to other Bluetooth devices — it broadcasts its presence so that other devices within range can detect it.
For security reasons, many devices remain in discoverable mode for a limited time or until paired with another device. After the initial pairing, the devices will usually reconnect automatically.
Dangers of discoverable mode
- Unauthorized pairing. If your device is in discoverable mode, someone nearby may attempt to pair with it. Though most devices require confirmation or a pairing code, not all have this security measure.
- Eavesdropping. Malicious actors can intercept the communication between Bluetooth devices. If they can access the pairing process, they might be able to decrypt the data being transferred between the paired devices, leading to potential data leaks.
- Bluetooth-based attacks. There are various known vulnerabilities and exploits related to Bluetooth. If a device is discoverable, it’s easier for attackers to target and exploit these vulnerabilities. Examples of such attacks include BlueBorne, which can spread malware between Bluetooth devices, or Bluesnarfing, where attackers can gain unauthorized access to information on a Bluetooth-enabled device.
- Device identification. Prolonged or unnecessary discoverability can let malicious actors identify and catalog devices in a particular area. This can be a concern, especially in high-security environments.
- Battery drain. While not a security concern, keeping a device continuously in discoverable mode can consume more power, leading to faster battery drain.
- Potential for spoofing. Malicious actors can imitate or “spoof” a known device’s Bluetooth ID, tricking users into pairing with the attacker’s device instead of the intended device.