CVE entry · CVE-2023-4346
CVE-2023-4346: KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
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.
- Actively exploited: added to CISA’s KEV catalog on July 15, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: July 29, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes KNX Association KNX Protocol Connection Authorization Option 1, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.