Vulnerability in Cypress Cyw20735b1
CVE-2021-34148
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 a greater ACL Length 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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (45.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Public proof-of-concept exploits
References
- www.cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-trans… (Vendor Advisory)
- dl.packetstormsecurity.net/papers/general/braktooth.pdf (Technical Description, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-34148?
- CVE-2021-34148 is a medium-severity vulnerability in Cypress Cyw20735b1. CVSS score: 6.5/10. Published 2021-09-07.
- How severe is CVE-2021-34148?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-34148 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.