Rockwell Automation Allen-Bradley MicroLogix controller 1100, 1200, 1400, and 1500; SLC 500 controller platform; and PLC-5 controller platform, when Static status is not enabled, allow remote attackers to cause a denial of service via messages that trigger modification of status bits.
https://rockwellautomation.custhelp.com/app/answers/detail/a_id/511407
http://www.us-cert.gov/control_systems/pdf/ICSA-12-342-01.pdf