The DataSim and DataPid demonstration clients in Cogent Real-Time Systems Cogent DataHub before 7.3.0 OPC DataHub before 6.4.22 Cascade DataHub before 6.4.22 on Windows and DataHub QuickTrend before 7.3.0 allow remote servers to cause a denial of service (incorrect pointer access and client crash) via malformed data in a formatted text command.