The OTP Login With Phone Number, OTP Verification plugin for WordPress is vulnerable to authentication bypass in versions 1.8.50 through 1.8.60. This is due to the Firebase verification flow in the lwpajaxregister AJAX handler not binding the Firebase session to the phone number supplied in the request. The idehweblwpactivatethroughfirebase() function validates that a Firebase OTP session is legitimate, but the phoneNumber returned by Firebase is never compared against the victim's stored phone number. This makes it possible for unauthenticated attackers to authenticate as any user who has a phone number stored in user meta, including administrators, by verifying their own Firebase session and supplying the victim's phone number in the same request.