The Invoice Generator plugin for WordPress is vulnerable to privilege escalation due to a missing capability check on the pravelinvoiceeditaccount() AJAX action in versions up to, and including, 1.0.0. The handler is exposed via wpajaxnoprivpravelinvoiceeditaccount, accepts an attacker-controlled userid and useremail from POST data, and calls wpupdateuser() without verifying authentication, ownership, or a nonce. This makes it possible for unauthenticated attackers to change the email address of any user, including administrators, and then trigger WordPress's password reset flow to gain access to the targeted account.