Affected: Omron CJ-series and CS-series CPU modules

The Omron FINS protocol has an authenticated feature to prevent access to memory regions. Authentication is susceptible to bruteforce attack, which may allow an adversary to gain access to protected memory. This access can allow overwrite of values including programmed logic.

Omron CJ/CS/CP series programmable logic controllers use the FINS protocol, which is vulnerable to brute-force attacks. The controllers do not enforce any rate limit on password guesses to password-protected memory regions.