The My Sticky Bar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.6.6. This is due to missing or incorrect nonce validation in mystickymenu-contact-leads.php. This makes it possible for unauthenticated attackers to trigger the export of a CSV file containing contact leads via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. Because the CSV file is exported to a public location, it can be downloaded during a very short window of time before it is automatically deleted by the export function.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.