The Classified Listing – Classified ads & Business Directory Plugin plugin for WordPress is vulnerable to unauthorized modification of data that can lead to privilege escalation due to a misconfigured check on the 'rtcl_import_settings' function in all versions up to, and including, 3.1.15.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to update limited arbitrary options on the WordPress site. This can be leveraged to update the Subscriber role with Administrator-level capabilities to gain administrative user access to a vulnerable site. The vulnerability is limited in that the option updated must have a value that is an array.