CVE-2021-34146

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-07 · updated 2026-06-17

Description

The Bluetooth Classic implementation in the Cypress CYW920735Q60EVB does not properly handle the reception of continuous unsolicited LMP responses, allowing attackers in radio range to trigger a denial of service and restart (crash) of the device by flooding it with LMP_AU_Rand packets after the paging procedure.

Affected products

Cypress Cyw20735B1 Firmware: all versions
Cypress Cyw920735Q60Evb-01 Firmware: all versions

References

https://dl.packetstormsecurity.net/papers/general/braktooth.pdf
https://www.cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-transceiver-wireless-input-devices
https://dl.packetstormsecurity.net/papers/general/braktooth.pdf
https://www.cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-transceiver-wireless-input-devices

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