Bluetooth Cross-Transport Key Derivation (BLUR)
Description
Bluetooth Cross-Transport Key Derivation (BLUR)Risk Assesment: 9.8
CWE
CVE
Attack Surfaces
Controller Implementation (MITRE EMB3D PID-11)
Security Manager Protocol (MITRE EMB3D PID-4113)
Attack Vectors
Entropy downgrade (MITRE EMB3D TID-411)
Cross-transport pairing
No IO downgrade (MITRE EMB3D TID-411)
Defenses
Prevent cross-transport key tampering, Disable key overwrite with weaker keys
Enforce strong association mechanisms, Track associations for paired devices and abort on downgrade request
Prevent role switching, Track asymmetries in roles between BT and BLE