Huawei mobile phones Ever-L29B versions earlier than 10.0.0.180(C185E6R3P3), earlier than 10.0.0.180(C432E6R1P7), earlier than 10.0.0.180(C636E5R2P3); HUAWEI Mate 20 RS versions earlier than 10.0.0.175(C786E70R3P8); HUAWEI Mate 20 X versions earlier than 10.0.0.176(C00E70R2P8); and Honor Magic2 versions earlier than 10.0.0.175(C00E59R2P11) have an improper authorization vulnerability. Due to improper authorization of some function, attackers can bypass the authorization to perform some operations.
The Bluetooth BR/EDR specification up to and including version 5.1 permits sufficiently low encryption key length and does not prevent an attacker from influencing the key length negotiation. This allows practical brute-force attacks (aka "KNOB") that can decrypt traffic and inject arbitrary ciphertext without the victim noticing.