The Ninja Forms Contact Form WordPress plugin before 3.6.13 unserialises the content of an imported file, which could lead to PHP object injections issues when an admin import (intentionally or not) a malicious file and a suitable gadget chain is present on the blog.
The Ninja Forms Contact Form WordPress plugin before 3.6.10 does not sanitise and escape field labels, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.
The Ninja Forms Contact Form WordPress plugin before 3.6.10 does not sanitize and escape some imported data, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.
The Ninja Forms Contact Form WordPress plugin before 3.6.4 does not escape keys of the fields POST parameter, which could allow high privilege users to perform SQL injections attacks
The Ninja Forms WordPress plugin is vulnerable to sensitive information disclosure via the bulk_export_submissions function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to export all Ninja Forms submissions data via the /ninja-forms-submissions/export REST API which can include personally identifiable information.
The Ninja Forms WordPress plugin is vulnerable to arbitrary email sending via the trigger_email_action function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to send arbitrary emails from the affected server via the /ninja-forms-submissions/email-action REST API which can be used to socially engineer victims.