CVE-2023-4346KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability

BOD 26-04 remediation window

With CISA's SSVC answers for this CVE (automatable: yes, technical impact: partial), BOD 26-04 Table 1 gives 3 days on a publicly exposed asset (row 2) and 14 days on an asset that is not publicly exposed (row 10) ^S06. CISA set the catalogue due date at 14 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets ^S07. The directive binds US federal civilian executive branch agencies only.

What CISA says

Short description

KNX Association KNX Protocol Connection Authorization Option 1 contains an overly restrictive account lockout mechanism vulnerability that could allow an attacker to purge all devices without additional security options enabled and set a BCU key to lock the device.

Required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Notes

https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2023-4346

CWE in the catalogue

CWE-645

Official links

• CISA KEV catalogue entry cisa.gov
• NVD record nvd.nist.gov

Vendor advisory and patch links

No vendor advisory linked by NVD.

Links in CISA's notes

• https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
• https://nvd.nist.gov/vuln/detail/CVE-2023-4346

NVD details

CWE (NVD)

CWE-645 by ics-cert@hq.dhs.gov

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS versions in NVD

V31

Last modified in NVD

2026-07-16T05:16:16.603

Where each value comes from

This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.