The (1) Catapult DNP3 I/O driver before 7.2.0.60 and the (2) GE Intelligent Platforms Proficy DNP3 I/O driver before 7.20k, as used in DNPDrv.exe (aka the DNP master station server) in GE Intelligent Platforms Proficy HMI/SCADA - CIMPLICITY and iFIX, allow physically proximate attackers to cause a denial of service (infinite loop) via crafted input over a serial line.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.