The jQuery Hover Footnotes plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.4. This is due to missing or incorrect nonce validation on the jqFootnotes_options_subpanel function. This makes it possible for unauthenticated attackers to update the plugin's settings with arbitrary values that, because option values such as jqfoot_anchor_open, jqfoot_anchor_close, and jqfoot_title are echoed unescaped into frontend page content, can be chained into persistent Cross-Site Scripting affecting all site visitors via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Successful exploitation of the CSRF vulnerability can be chained into stored Cross-Site Scripting, as the overwritten option values are persisted via update_option() without sanitization and rendered unescaped on the frontend.