PatchTheCVECVE-2021-34146: The Bluetooth Classic implementation in the Cypress CYW920735Q60EVB does not properly handle the reception of
CVE-2021-34146 is a medium-severity flaw (CVSS 6.5) affecting cyw920735q60evb-01 firmware, cyw20735b1 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Adjacent network |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.6% (top 52%) |
| CISA exploited list | No |
| Published | 2021-09-07 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-34146?
cyw920735q60evb-01 firmware: mitigate or apply the listed mitigation; cyw20735b1 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2021-34146 being exploited?
CVE-2021-34146 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-34146 affect?
CVE-2021-34146 affects cyw920735q60evb-01 firmware, cyw20735b1 firmware. Severity is medium (CVSS 6.5). 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
How urgent is CVE-2021-34146?
Priority 35/100. No elevated risk signals yet.