The DNP3 feature on Rockwell Automation Allen-Bradley MicroLogix 1400 1766-Lxxxxx A FRN controllers 7 and earlier and 1400 1766-Lxxxxx B FRN controllers before 15.001 allows remote attackers to cause a denial of service (process disruption) via malformed packets over (1) an Ethernet network or (2) a serial line.
https://www.cisa.gov/news-events/ics-advisories/icsa-14-254-02
https://rockwellautomation.custhelp.com/app/answers/detail/a_id/620295
https://ics-cert.us-cert.gov/advisories/ICSA-14-254-02
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2014/icsa-14-254-02.json