Pixel Tag Manager for WooCommerce < 2.2.3 - Contributor+ Stored XSS via Google Tag Manager Container ID

The Pixel Tag Manager for WooCommerce WordPress plugin before 2.2.3 does not perform a capability check in one of its AJAX actions, and exposes the nonce protecting it to any user able to access the admin dashboard, allowing users with a role as low as Contributor to overwrite the Pixel Tag Manager for WooCommerce WordPress plugin before 2.2.3's tracking configuration and have arbitrary JavaScript executed in the browsers of all visitors, including administrators.