The FlowForms – Conversational Form Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.1.1 via the update_form due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to modify the content, design, and settings of, as well as publish or revert, any form on the site — including forms owned by administrators — by supplying an arbitrary form ID in the REST URL.
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L694
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L654
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L603
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L562
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L493
https://plugins.trac.wordpress.org/browser/flowforms/tags/1.1.1/includes/class-rest-api.php#L48