Omron CJ1M unit v4.0 and prior has improper access controls on the memory region where the UM password is stored. If an adversary issues a PROGRAM AREA WRITE command to a specific memory region, they could overwrite the password. This may lead to disabling UM protections or setting a non-ASCII password (non-keyboard characters) and preventing an engineer from viewing or modifying the user program.

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 interpret…

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.