TI’s BLE stack caches and reuses the LTK’s property for a bonded mobile. A LTK can be an unauthenticated-and-no-MITM-protection key created by Just Works or an authenticated-and-MITM-protection key created by Passkey Entry, Numeric Comparison or OOB. Assume that a victim mobile uses secure pairing to pair with a victim BLE device based on TI chips and generate an authenticated-and-MITM-protection LTK. If a fake mobile with the victim mobile’s MAC address uses Just Works and pairs with the victim device, the generated LTK still has the property of authenticated-and-MITM-protection. Therefore, the fake mobile can access attributes with the authenticated read/write permission.

The Bluetooth Low Energy peripheral implementation on Texas Instruments SIMPLELINK-CC2640R2-SDK through 3.30.00.20 and BLE-STACK through 1.5.0 before Q4 2019 for CC2640R2 and CC2540/1 devices does not properly restrict the advertisement connection request packet on reception, allowing attackers in radio range to cause a denial of service (crash) via a crafted packet.

Texas Instruments BLE-STACK v2.2.1 for SimpleLink CC2640 and CC2650 devices allows remote attackers to execute arbitrary code via a malformed packet that triggers a buffer overflow.