The miniOrange 2FA WordPress plugin before 6.3.1, miniOrange 2FA WordPress plugin before 19.3...

The miniOrange 2FA WordPress plugin before 6.3.1, miniOrange 2FA WordPress plugin before 19.3 does not scope its second-factor attempt limit to the account being attacked, keying it instead to an identifier the client supplies and can change at will, allowing an attacker who already knows a victim's password to make unlimited one-time-passcode guesses and defeat the second factor. A second validation endpoint applies no attempt limit at all.