In Emerson Ovation OCR400 Controller 3.3.1 and earlier, a heap-based buffer overflow vulnerability in the embedded third-party FTP server involves improper handling of a long command to the FTP service, which may cause memory corruption that halts the controller or leads to remote code execution and escalation of privileges.
https://ics-cert.us-cert.gov/advisories/ICSA-19-148-01