Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder

The Everest Forms plugin for WordPress is vulnerable to Arbitrary File Read and Deletion in all versions up to, and including, 3.4.4. This is due to the plugin trusting attacker-controlled old_files data from public form submissions as legitimate server-side upload state, and converting attacker-supplied URLs into local filesystem paths using regex-based string replacement without canonicalization or directory boundary enforcement. This makes it possible for unauthenticated attackers to read arbitrary local files (e.g., wp-config.php) by injecting path-traversal payloads into the old_files upload field parameter, which are then attached to notification emails. The same path resolution is also used in the post-email cleanup routine, which calls unlink() on the resolved path, resulting in the targeted file being deleted after being attached. This can lead to full site compromise through disclosure of database credentials and authentication salts from wp-config.php, and denial of service through deletion of critical files. Prerequisite: The form must contain a file-upload or image-upload field, and disable storing entry information.

The Everest Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.4.3 via deserialization of untrusted input from form entry metadata. This is due to the html-admin-page-entries-view.php file calling PHP's native unserialize() on stored entry meta values without passing the allowed_classes parameter. This makes it possible for unauthenticated attackers to inject a serialized PHP object payload through any public Everest Forms form field. The payload survives sanitize_text_field() sanitization (serialization control characters are not stripped) and is stored in the wp_evf_entrymeta database table. When an administrator views entries or views an individual entry, the unsafe unserialize() call processes the stored data without class restrictions.

The The Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.4.1. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

The Everest Forms – Contact Form, Quiz, Survey, Newsletter & Payment Form Builder for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'form_id' parameter in all versions up to, and including, 3.1.1 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 The Everest Forms – Contact Form, Quiz, Survey, Newsletter & Payment Form Builder for WordPress plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.1.1. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for authenticated attackers, with Subscriber-level access and above, to execute arbitrary shortcodes.

The Everest Forms – Contact Form, Quiz, Survey, Newsletter & Payment Form Builder for WordPress plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.1.1 via deserialization of untrusted input from the 'field_value' parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

The Everest Forms – Contact Forms, Quiz, Survey, Newsletter & Payment Form Builder for WordPress plugin for WordPress is vulnerable to arbitrary file upload, read, and deletion due to missing file type and path validation in the 'format' method of the EVF_Form_Fields_Upload class in all versions up to, and including, 3.0.9.4. This makes it possible for unauthenticated attackers to upload, read, and delete arbitrary files on the affected site's server which may make remote code execution, sensitive information disclosure, or a site takeover possible.