Improper Restriction of Excessive Authentication Attempts vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F/iQ-R Series CPU modules Web server function allows a remote unauthenticated attacker to prevent legitimate users from logging into the Web server function for a certain period after the attacker has attempted to log in illegally by continuously attempting unauthorized login to the Web server function. The impact of this vulnerability will persist while the attacker continues to attempt unauthorized login.