The Spreadsheet Integration plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 3.8.2. This is due to improper nonce validation within the class-wpgsi-show.php script. This makes it possible for unauthenticated attackers to publish arbitrary posts, including private, granted they can trick a site administrator into performing an action such as clicking on a link.
CWE-352