The WP Survey Plus WordPress plugin through 1.0 does not have any authorisation and CSRF checks in place in its AJAX actions, allowing any user to call them and add/edit/delete Surveys. Furthermore, due to the lack of sanitization in the Surveys' Title, this could also lead to Stored Cross-Site Scripting issues
https://wpscan.com/vulnerability/78405609-2105-4011-b18e-1ba5f438972d