A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4 that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer until the device is rebooted via a SESSION_REQUEST frame with a modified total length field.