UsersWP < 1.2.66 - Subscriber+ Arbitrary File Deletion via File Upload Field

Description

The plugin is vulnerable to Arbitrary File Deletion due to insufficient validation of file-field values in the UsersWP_Validation::validate_fields() function (which falls through to sanitize_text_field() for fields of type 'file', leaving directory-traversal sequences intact) combined with the UsersWP_Forms::upload_file_remove() AJAX handler building the deletion target from the uploads basedir concatenated with the attacker-controlled metadata value without any realpath canonicalization or uploads-directory boundary check before calling unlink(). This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary files on the affected site's server, including wp-config.