CVE-2019-19196

The Bluetooth Low Energy Secure Manager Protocol (SMP) implementation on Telink Semiconductor BLE SDK versions before November 2019 for TLSR8x5x through 3.4.0, TLSR823x through 1.3.0, and TLSR826x through 3.3 devices accepts a pairing request with a key size greater than 16 bytes, allowing an attacker in radio range to cause a buffer overflow and denial of service (crash) via crafted packets.

Recent assessments:

pbarry-r7 at April 16, 2020 2:28pm UTC reported:

This vuln is part of a related batch named SweynTooth from researchers at the Singapore University of Technology and Design. The SweynTooth vulnerabilities lie within certain Bluetooth Low Energy (BLE) SDKs for Systems-on-a-Chip (SoC), which can make proliferating fixes to affected devices in the field a slow going.

Vulnerable devices need only to be within BLE radio range for an attacker to target. An exploit can trigger a buffer overflow (BOF) to crash a vulnerable target, effectively a DoS. Because the attack vector is a BOF, the possibility does exist for a carefully constructed attack to bypass security by overwriting the security nonce and then leak user information. A detailed explanation can be found here in the original disclosure, as well as some potentially vulnerable devices in this list. It appears the SoC manufacturer has issued fixes for their vulnerable SDK(s).

EDIT: Attacker Value for this item largely depends on the type of device the vulnerable target is and behavior the device exhibits when successfully exploited.

Assessed Attacker Value: 3
Assessed Attacker Value: 3Assessed Attacker Value: 4