Security readout for executives and security teams
CVE-2021-3431 is a Zephyr Bluetooth issue where repeated Link Layer feature requests can trigger an assertion and disrupt availability. The known impact is limited: no confidentiality or integrity impact is reported, and exploitation requires adjacent Bluetooth proximity. Exposure is most likely in Bluetooth-enabled products running affected Zephyr versions, especially devices using Zephyr v2.5.0 or later as described by the CVE source. Devices without Bluetooth functionality are unlikely to be affected. Treat as a targeted availability risk for Bluetooth-enabled embedded products, not a broad enterprise emergency. Prioritize products where downtime, physical access constraints, or safety obligations make local denial-of-service more consequential. Mitigation focus: Check the Zephyr security advisory for supported fixed versions or workarounds.; Identify products and firmware builds using affected Zephyr Bluetooth components.; Upgrade or patch through vendor-supported firmware releases when available..
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.
CWE-617: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-3431 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
- Medium
- CVSS
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
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.
Reachable Assertion
Reachable Assertion represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.