CVE-2018-17924
Rockwell Automation MicroLogix 1400 Controllers and 1756 ControlLogix Communications Modules An unauthenticated, remote threat actor could send a CIP connection request to an affected device, and upon successful connection, send a new IP configuration to the affected device even if the controller in the system is set to Hard RUN mode. When the affected device accepts this new IP configuration, a loss of communication occurs between the device and the rest of the system as the system traffic is still attempting to communicate with the device via the overwritten IP address.
Source: CVE-2018-17924