CVE-2021-4407

The Custom Banners plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.2.2 This is due to missing or incorrect nonce validation on the saveCustomFields() function. This makes it possible for unauthenticated attackers to save custom fields via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Source: CVE-2021-4407