The Omron SYSMAC Cx product family PLCs (CS series, CJ series, and CP series) through 2022-05-18 lack cryptographic authentication. They utilize the Omron FINS (9600/TCP) protocol for engineering purposes, including downloading projects and control logic to the PLC. This protocol has authentication flaws as reported in FSCT-2022-0057. Control logic is downloaded to PLC volatile memory using the FINS Program Area Read and Program Area Write commands or to non-volatile memory using other commands from where it can be loaded into volatile memory for execution. The logic that is loaded into and executed from the user program area exists in compiled object code form. Upon execution, these object codes are first passed to a dedicated ASIC that determines whether the object code is to be executed by the ASIC or the microprocessor. In the former case, the object code is interpreted by the ASIC whereas in the latter case the object code is passed to the microprocessor for object code interpretation by a ROM interpreter. In the abnormal case where the object code cannot be handled by either, an abnormal condition is triggered and the PLC is halted. The logic that is downloaded to the PLC does not seem to be cryptographically authenticated, thus allowing an attacker to manipulate transmitted object code to the PLC and either execute arbitrary object code commands on the ASIC or on the microprocessor interpreter.

The Omron SYSMAC Nx product family PLCs (NJ series, NY series, NX series, and PMAC series) through 2022-005-18 lack cryptographic authentication. These PLCs are programmed using the SYMAC Studio engineering software (which compiles IEC 61131-3 conformant POU code to native machine code for execution by the PLC's runtime). The resulting machine code is executed by a runtime, typically controlled by a real-time operating system. The logic that is downloaded to the PLC does not seem to be cryptographically authenticated, allowing an attacker to manipulate transmitted object code to the PLC and execute arbitrary machine code on the processor of the PLC's CPU module in the context of the runtime. In the case of at least the NJ series, an RTOS and hardware combination is used that would potentially allow for memory protection and privilege separation and thus limit the impact of code execution. However, it was not confirmed whether these sufficiently segment the runtime from the rest of the RTOS.

In Omron CS series, CJ series, and CP series PLCs through 2022-05-18, the password for access to the Web UI is stored in memory area D1449...D1452 and can be read out using the Omron FINS protocol without any further authentication.

Omron CS series, CJ series, and CP series PLCs through 2022-05-18 use cleartext passwords. They feature a UM Protection setting that allows users or system integrators to configure a password in order to restrict sensitive engineering operations (such as project/logic uploads and downloads). This password is set using the OMRON FINS command Program Area Protect and unset using the command Program Area Protect Clear, both of which are transmitted in cleartext.