The Oliver POS – A WooCommerce Point of Sale (POS) plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.4.2.3 via the logging functionality. This makes it possible for unauthenticated attackers to extract sensitive data including the plugin's clientToken, which in turn can be used to change user account information including emails and account type. This allows attackers to then change account passwords resulting in a complete site takeover. Version 2.4.2.3 disabled logging but left sites with existing log files vulnerable.