Security readout for executives and security teams
CVE-2021-3435 is an information leak in Zephyr RTOS Bluetooth L2CAP handling. The public record identifies Zephyr v2.4.0 and v2.5.0 as affected. Impact is limited to confidentiality, with no integrity or availability impact stated. Exposure is most likely in products or firmware built on Zephyr RTOS v2.4.0 or v2.5.0, especially where Bluetooth L2CAP functionality is enabled. The provided sources do not identify specific downstream devices. Handle as a moderate confidentiality risk. It does not justify emergency response from the provided evidence, but embedded products can be hard to patch, so ownership and firmware exposure should be confirmed promptly. Mitigation focus: Inventory firmware and SBOMs for Zephyr v2.4.0 or v2.5.0.; Review the Zephyr GitHub advisory for fixed versions or vendor-specific guidance.; Prioritize remediation for Bluetooth-enabled products using affected Zephyr releases..
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
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ATT&CK lookup starting points
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Open ATT&CK lookupCVE-2021-3435 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
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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:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N2.51.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
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.
Use of Uninitialized Resource
Use of Uninitialized Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.