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.
The AJAX action, wp_ajax_ninja_forms_sendwp_remote_install_handler, did not have a capability check on it, nor did it have any nonce protection, therefore making it possible for low-level users, such as subscribers, to install and activate the SendWP Ninja Forms Contact Form – The Drag and Drop Form Builder for WordPress WordPress plugin before 3.4.34 and retrieve the client_secret key needed to establish the SendWP connection while also installing the SendWP plugin.
In the Ninja Forms Contact Form WordPress plugin before 3.4.34.1, low-level users, such as subscribers, were able to trigger the action, wp_ajax_nf_oauth, and retrieve the connection url needed to establish a connection. They could also retrieve the client_id for an already established OAuth connection.
In the Ninja Forms Contact Form WordPress plugin before 3.4.34, the wp_ajax_nf_oauth_connect AJAX action was vulnerable to open redirect due to the use of a user supplied redirect parameter and no protection in place.
The wp_ajax_nf_oauth_disconnect from the Ninja Forms Contact Form – The Drag and Drop Form Builder for WordPress WordPress plugin before 3.4.34 had no nonce protection making it possible for attackers to craft a request to disconnect a site's OAuth connection.