CVE-2021-34145
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1...
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
5.3
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
CVE-2021-34145- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 2.9 Low
AV:A/AC:M/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
CVE List No score
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
CVE-2021-34145- Updated
- 2026-11-02
EUVDEUVD-2021-20807 No score
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
EUVD-2021-20807- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7j4h-6cq9-gmjv No score
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1...
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
GHSA-7j4h-6cq9-gmjv- Updated
- 2026-11-02
OSV
5.3
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
CVE-2021-34145- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-34145
5.3
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
DEBIAN-CVE-2021-34145- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-34145
5.3
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices does not properly handle the reception of LMP_max_slot with an invalid Baseband packet type (and LT_ADDRESS and LT_ADDR) after completion of the LMP setup procedure, allowing attackers in radio range to trigger a denial of service (firmware crash) via a crafted LMP packet.
- Record
UBUNTU-CVE-2021-34145- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
bluez-firmwareDebian:12 |
before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1 |
1.2-8 |
bluez-firmwareDebian:13 |
before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1 |
1.2-8 |
bluez-firmwareDebian:14 |
before 1.2-8, plus listed versions 1.0-21.0-31.2-11.2-21.2-3 Show 6 moreShow less1.2-41.2-51.2-61.2-71.2-7~bpo11+11.2-8~bpo11+1 |
1.2-8 |
bluez-firmwareUbuntu:22.04:LTS |
All versions, plus listed versions 1.2-7 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34145 is a medium vulnerability (CVSS 5.3) in Cypress Wireless Internet Connectivity For Embedded Devices, published September 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.52%, the 44th percentile. Fixed in bluez-firmware 1.2-8.
References
cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-transceiver-wireless-input-devices
dl.packetstormsecurity.net/papers/general/braktooth.pdf
nvd.nist.gov/vuln/detail/CVE-2021-34145
github.com/advisories/GHSA-7j4h-6cq9-gmjv
security-tracker.debian.org/tracker/CVE-2021-34145
ubuntu.com/security/CVE-2021-34145
github.com/RPi-Distro/bluez-firmware/commit/31ad68831357d2019624004f1f0846475671088f
cve.org/CVERecord?id=CVE-2021-34145