The Custom Fields Account Registration For Woocommerce WordPress plugin before 1.4 does not prevent its custom registration fields from writing to the user capabilities meta key on sites that use a non-default database table prefix, so an unauthenticated user who registers an account can be granted the administrator role when a correspondingly named field has been configured.
https://wpscan.com/vulnerability/36aaba38-3143-4e80-8386-748632ff6704/