The MStore API – Create Native Android & iOS Apps On The Cloud plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including, 4.14.7. This is due to insufficient verification on the 'phone' parameter of the 'firebase_sms_login' and 'firebase_sms_login_v2' functions. This makes it possible for unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the email address or phone number. Additionally, if a new email address is supplied, a new user account is created with the default role, even if registration is disabled.