A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists in Modicon M580, Modicon M340, Modicon Quantum, Modicon Premium (see security notification for specific versions) which could cause a Denial of Service of the controller when reading specific memory blocks using Modbus TCP.
https://www.us-cert.gov/ics/advisories/icsa-20-016-01