CVE-2023-4346 | defend.network

What is CVE-2023-4346?

KNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and users being unable to reset them to gain access to the device. The BCU key feature on the devices can be used to create a password for the device, but this password can often not be reset without entering the current password. If the device is configured to interface with a network, an attacker with access to that network could interface with the KNX installation, purge all devices without additional security options enabled, and set a BCU key, locking the device. Even if a device is not connected to a network, an attacker with physical access to the device could also exploit this vulnerability in the same way.

CVSS7.5 NVD 3.1

SeverityHIGH

Exploitation In the wild In CISA KEV

EPSS1% · P70

Triage statusActive Exploit

ActionPatch immediately

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

CWECWE-645

NVD published2023-08-29

NVD last modified2026-07-16

Timeline

2023-08-29Published to the U.S. National Vulnerability Database (NVD)
2026-07-15Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-07-16NVD record last updated
2026-07-29CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability

Added to KEV2026-07-15

Federal patch deadline2026-07-29

Known ransomware useUnknown

Affected product

KNX Association KNX Protocol Connection Authorization Option 1

Remediation Steps

Apply the vendor security update for KNX Association KNX Protocol Connection Authorization Option 1 as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 2 of August 2026 (August 10 – 16)
Vulnerability Priority Report – Week 1 of August 2026 (August 3 – 9)
Vulnerability Priority Report – Week 4 of July 2026 (July 27 – August 2)
Vulnerability Priority Report – Week 3 of July 2026 (July 20 – 26)
Vulnerability Priority Report – Week 2 of July 2026 (July 13 – 19)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.