FireBox < 3.1.11 - Authenticated (Author+) Remote Code Execution to Privilege Escalation

Description

The FireBox – WooCommerce Popup Builder, Exit Intent Popup, Email Optin & Cart Abandonment plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 3.1.10 via the value function. This is due to a trivially bypassable regex blacklist in Executer::allowedToRun() that fails to block WordPress core functions such as wp_insert_user, update_option, and file_put_contents, combined with no sanitization of PHP condition rule values stored via the firebox_meta REST endpoint. This makes it possible for authenticated attackers, with author-level access and above, to execute code on the server. On sites upgraded from a version prior to 3.1.10, the Migrator::preserveCampaignRoleAccess() function automatically grants the edit_fireboxes and publish_fireboxes capabilities to the Author role, lowering the effective entry point to Author-level access.