A CWE-191: Integer Underflow (Wrap or Wraparound) vulnerability exists that could cause a denial of service of the controller due to memory access violations when using the Modbus TCP protocol. Affected products: Modicon M340 CPU (part numbers BMXP34)(V3.40 and prior), Modicon M580 CPU (part numbers BMEP and BMEH)(V3.22 and prior), Legacy Modicon Quantum/Premium(All Versions), Modicon Momentum MDI (171CBU)(All Versions), Modicon MC80 (BMKC80)(V1.7 and prior)

An Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability exists in Modicon Quantum 140 NOE771x1 version 6.9 and earlier, which could cause denial of service when the module receives an IP fragmented packet with a length greater than 65535 bytes. The module then requires a power cycle to recover.