miniOrange OTP Login, Verification and SMS Notifications <= 5.5.8 - Unauthenticated Authentication Bypass via Delay OTP Grace State

The miniOrange OTP Login, Verification and SMS Notifications plugin for WordPress is vulnerable to Authentication Bypass in versions up to, and including, 5.5.8 via the mo_by_pass_login() function. This is due to mo_delay_otp_process() short-circuiting the authentication flow before password validation or the administrator intent gate (added in 5.5.6) can run, combined with the Delay OTP grace flag (mov_last_verified_dttm) being stored as a user_meta row keyed solely by target user ID with no binding to the originating session, cookie, IP address, or device. This makes it possible for unauthenticated attackers to authenticate as any WordPress user — including administrators — by submitting only a known username with the mo_wp_login_intent=otp parameter and any non-empty password, thereby inheriting a legitimate user's open Delay OTP grace window without ever supplying correct credentials. Exploitation requires the site to have OTP-only login (wp_login_skip_password=1, wp_login_skip_password_fallback=0) and Delay OTP Verification (wp_login_delay_otp=1) enabled, and the target account must currently be within its configured Delay OTP interval.