CVE-2020-36731
The Flexible Checkout Fields for WooCommerce plugin for WordPress is vulnerable to Unauthenticated Arbitrary Plugin Settings update, in addition to Stored Cross-Site Scripting in versions up to, and including, 2.3.1. This is due to missing authorization checks on the updateSettingsAction() function which is called via an admin_init hook, along with missing sanitization and escaping on the settings that are stored.
Source: CVE-2020-36731