MemberPress Corporate Accounts <= 1.5.39 - Authenticated (Subscriber+) Privilege Escalation via Mass Assignment in Sub-Account Creation

The MemberPress Corporate Accounts plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 1.5.39. This is due to a mass assignment vulnerability in the 'add_sub_account_user' function that passes the raw 'userdata' array to 'wp_insert_user' without filtering dangerous keys like role or ID. This makes it possible for authenticated attackers, with subscriber-level access and above who hold a corporate account, to create new administrator accounts or hijack existing administrator accounts by overwriting their email addresses. The vulnerability was partially patched in version 1.5.39.