Everest Forms vulnerabilities

The Everest Forms plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to and including 3.4.4. The load_previous_field_value() method accepts arbitrary URL values from $_POST data for upload fields without domain restriction, which are then passed to wp_remote_head(). This allows unauthenticated attackers to force the WordPress server to make outbound HTTP HEAD requests to arbitrary URLs.

The Everest Forms plugin for WordPress up to version 3.5.2 is vulnerable to authorization bypass due to improper verification of user permissions. Authenticated attackers with delegated form management access can activate arbitrary already-installed WordPress plugins, including previously deactivated or vulnerable ones, without holding the activate_plugins capability. This requires holding a delegated Everest Forms capability, which administrators can assign to non-administrators.

The Everest Forms WordPress plugin before version 3.5.0 incorrectly restricts access to several REST API endpoints belonging to its onboarding assistant. The capability check is only applied when an attacker-controllable request header holds a specific value, so it can be bypassed by omitting or changing that header.

The Everest Forms WordPress plugin before version 3.5.0 does not reliably delete temporary CSV files generated during email notification processing, leaving them publicly accessible in the uploads directory. This allows unauthenticated attackers to retrieve other users' form submission records via predictable, enumerable filenames.