WordPress miniOrange OTP Plugin Authentication Bypass Vulnerability

The miniOrange OTP Login, Verification and SMS Notifications plugin for WordPress is vulnerable to an Authentication Bypass via the mo_wp_login_intent parameter in all versions up to and including 5.5.5.

The flaw is due to a missing password-intent guard in the skip_pass_fallback-enabled configuration branch of the mo_by_pass_login() function. Administrator role membership alone is treated as sufficient authentication whenever the unauthenticated, unverified POST parameter mo_wp_login_intent is submitted with the value otp, causing mo_get_user() to skip wp_authenticate_username_password() and resolve a WP_User purely from a username lookup.

This makes it possible for unauthenticated attackers to log in as any existing administrator account by supplying only a known username and an empty password alongside mo_wp_login_intent=otp, with no password or OTP verification required.

Exploitation is conditional on a site administrator having enabled the following plugin options:

• WP Login OTP
• Login with Only OTP
• Allow Users to Login with Username and Password
• Admin OTP Bypass