CVE-2021-34146

The Bluetooth Classic implementation in the Cypress CYW920735Q60EVB does not properly handle the...

6.5 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Adjacent network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.59%Down 0.2 points since Sep 7, 2021

What each source reports

NVD Score used 6.5

Record: CVE-2021-34146
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 6.1 MediumAV:A/AC:L/Au:N/C:N/I:N/A:C
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-34146
Updated: 2026-11-02

EUVDEUVD-2021-20808 No score

Record: EUVD-2021-20808
Updated: 2026-11-03

GitHub AdvisoriesGHSA-jg54-6p86-rp5q No score

The Bluetooth Classic implementation in the Cypress CYW920735Q60EVB does not properly handle the...

Record: GHSA-jg54-6p86-rp5q
Updated: 2026-11-02

OSV 6.5

Record: CVE-2021-34146
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-34146 6.5

Record: DEBIAN-CVE-2021-34146
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-34146 6.5

Record: UBUNTU-CVE-2021-34146
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`bluez-firmware` Debian:12	before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less 1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1	1.2-8
`bluez-firmware` Debian:13	before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less 1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1	1.2-8
`bluez-firmware` Debian:14	before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less 1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1	1.2-8
`bluez-firmware` Ubuntu:22.04:LTS	All versions, plus listed versions 1.2-7	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-34146 is a medium vulnerability (CVSS 6.5) in Cypress Cyw20735b1 Firmware, published September 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.59%, the 48th percentile. Fixed in bluez-firmware 1.2-8.