Security readout for executives and security teams
Plain-English summary
A nearby attacker could crash Bluetooth firmware in certain Cypress CYW20735B1-based devices, causing a denial of service. The provided sources do not show data theft, remote code execution, active exploitation, or a named patch.
Executive priority
Treat this as an availability risk for affected Bluetooth-enabled assets, especially operational devices. Business urgency depends on where CYW20735B1 devices are deployed and whether short Bluetooth outages create safety, access, or productivity impact.
Technical view
CVE-2021-34145 affects Bluetooth Classic in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices. After LMP setup, improper handling of an invalid LMP_max_slot/Baseband packet type can trigger a firmware crash from radio range.
Likely exposure
Exposure is limited to devices using CYW20735B1 with Cypress WICED BT stack through 2.9.0. The CVE record’s structured affected fields are incomplete, so confirm via device BOMs, firmware manifests, or vendor documentation.
Exploitation context
The attacker must be within Bluetooth radio range. The cited CVE data describes denial of service only. KEV is false in the source bundle, and no cited source states active exploitation.
Researcher notes
The source bundle names packet-handling behavior but provides no CVSS, CWE, patch version, or exploit-in-the-wild evidence. Avoid broad product claims unless tied to confirmed CYW20735B1 and WICED BT stack version evidence.
Mitigation direction
- Identify products using CYW20735B1 and WICED BT stack through 2.9.0.
- Check Cypress or successor vendor guidance for firmware updates or mitigations.
- Prioritize devices where Bluetooth downtime affects safety, operations, or access.
- Reduce unnecessary Bluetooth exposure where operationally practical.
- Track vendor advisories because no specific fix is named in the bundle.
Validation and detection
- Review hardware BOMs for CYW20735B1 components.
- Confirm WICED BT stack version in firmware records.
- Check vendor advisories against deployed device models.
- Review device logs for unexplained Bluetooth firmware crashes or reboots.
- Document any unsupported devices requiring compensating controls.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-34145 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-transceiver-wireless-input-devicesCVE reference · x_refsource_MISC
- https://dl.packetstormsecurity.net/papers/general/braktooth.pdfCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.