CVE-2021-34147: Cypress Wireless Internet Connectivity For Embedded Devices

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 does not properly handle the reception of a malformed LMP timing accuracy response followed by multiple reconnections to the link slave, allowing attackers to exhaust device BT resources and eventually trigger a crash via multiple attempts of sending a crafted LMP timing accuracy response followed by a sudden reconnection with a random BDAddress.

Affected products

• Cypress Wireless Internet Connectivity For Embedded Devices: up to and including 2.9.0

Published 2021-09-07. Last modified 2026-06-17.