The Insert Headers and Footers Code – HT Script plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the ajaxdismiss function in all versions up to, and including, 1.1.2. This makes it possible for authenticated attackers, with Subscriber-level access and above, to update option values to 1/true on the WordPress site. This can be leveraged to update an option that would create an error on the site and deny access to legitimate users or be used to set some values to true, such as registration.