The MicroLogix 1400 is a programmable logic controller from Rockwell Automation widely used in industrial applications. It is affected by CVE-2017-16740, a Modbus TCP buffer overflow vulnerability fixed in firmware revision 21.003. The device was among the most exposed in Forescout's scan, making up 50% of results. Rockwell provides recovery guidance in advisory SD1790 for devices locked out by attackers.