Overly restrictive account lockout mechanism in KNX firmware - CVE-2023-4346
Published: July 17, 2026
Vulnerability identifier: #VU138375
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Green
CVE-ID: CVE-2023-4346
CWE-ID: CWE-645
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: KNX
Affected software:
KNX firmware
KNX firmware
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an overly restrictive account lockout mechanism in KNX Connection Authorization Option 1 handling when interfacing with the KNX installation to purge devices and set a BCU key. A remote attacker can purge devices without additional security options enabled and set a BCU key to cause a denial of service.
Devices are affected when no BCU key is currently set, and exploitation may leave users unable to regain access to the device or reset it.
How to mitigate CVE-2023-4346
Install security update from vendor's website.