The smooth-slider plugin before 2.7 for WordPress has SQL Injection via the wp-admin/admin.php?page=smooth-slider-admin current_slider_id parameter.
https://wpvulndb.com/vulnerabilities/8284
https://wordpress.org/plugins/smooth-slider/#developers
https://euvd.enisa.europa.eu/vulnerability/EUVD-2015-9294
http://cinu.pl/research/wp-plugins/mail_36e814da6ac4dd903be2c77cfbdd0afd.html