CVE-2021-37577 Details

A vulnerability exists in Bluetooth Low Energy (LE) and Basic Rate/Enhanced Data Rate (BR/EDR) Secure Connections pairing, as well as in Secure Simple Pairing using the Passkey entry protocol, across Bluetooth Core Specifications 2.1 to 5.3. This vulnerability may allow an unauthenticated man-in-the-middle attacker to intercept and identify the Passkey used during the pairing process. The attacker can achieve this by reflecting a crafted public key that matches the X coordinate of the original public key offered by the initiating device, along with the authentication evidence from that device. By doing so, the attacker could potentially complete the authenticated pairing process with the responding device using the correct Passkey, thereby exploiting the vulnerability.

Bluetooth devices should be updated to follow the recommendations in Bluetooth Core Specification 5.4, which advises rejecting public keys that have matching X coordinates, except in specific debugging scenarios. For devices that cannot be updated, it is recommended to disable pairing or bonding features.