The Extra Checkout Options (addon for Extra Product Options & Add-Ons for WooCommerce) plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.3.2. This is due to missing authorization and nonce validation in the eco_save_settings() function, which allows low-privileged authenticated users to modify the tc_eco_custom_file_types upload allowlist setting, combined with insufficient authorization on the wc_eco_upload_file AJAX action. This makes it possible for authenticated attackers, with Subscriber-level access and above, to allow PHP uploads, upload a PHP file using the frontend upload nonce exposed on cart and checkout pages, and achieve remote code execution. NOTE: This vulnerability was partially fixed in version 2.3.2.