The Styler for Ninja Forms plugin for WordPress is vulnerable to unauthorized modification of data that can lead to a denial of service due to a missing capability check on the deactivate_license function in all versions up to, and including, 3.3.4. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary option values on the WordPress site. This can be leveraged to delete an option that would create an error on the site and deny service to legitimate users. Note: This issue can also be used to add arbitrary options with an empty value.