PTC’s KEPServerEX Versions 6.0 to 6.14.263 are vulnerable to being made to read a recursively defined object that leads to uncontrolled resource consumption. KEPServerEX uses OPC UA, a protocol which defines various object types that can be nested to create complex arrays. It does not implement a check to see if such an object is recursively defined, so an attack could send a maliciously created message that the decoder would try to decode until the stack overflowed and the device crashed.
The Kepware DNP Master Driver for the KEPServerEX Communications Platform before 5.12.140.0 allows remote attackers to cause a denial of service (master-station infinite loop) via crafted DNP3 packets to TCP port 20000 and allows physically proximate attackers to cause a denial of service (master-station infinite loop) via crafted input over a serial line.