WP ManageNinja LLC Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder vulnerabilities

The Fluent Forms plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 6.2.5. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with Custom-level access and above, to read private form submissions, change submission statuses, permanently delete submissions, and modify global plugin settings.

The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'any attacker-chosen name matching the {get.NAME} placeholder (PoC uses 'proof')' parameter in all versions up to, and including, 6.2.14 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Exploitation requires a site administrator to have configured a Custom HTML field on a published form containing a {get.*} SmartCode inside a URL-accepting attribute such as iframe src or a href — a documented Fluent Forms feature.

The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via 'param' in all versions up to, and including, 6.2.8 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 6.2.8 via the 'transaction' parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to brute-force valid transaction hashes and view sensitive payment receipt data including customer name, email address, billing address, order items, payment method, and payment status belonging to other users. Because submission ID, form ID, and transaction creation time are either observable or guessable by an attacker, the effective brute-force space is bounded to approximately 900 candidates per second per (submission, form) pair, making exploitation practical without any prior authentication or account.

The Fluent Forms plugin for WordPress is vulnerable to incorrect authorization via the 'subscription_id' parameter in versions up to, and including, 6.2.1. This is due to insufficient ownership authorization checks in the payment cancellation AJAX flow. This makes it possible for authenticated attackers, with subscriber-level access and above, to submit cancellation requests for other users' subscriptions.