WP Maintenance Mode & Site Under Construction < 1.8.2 - Arbitrary Plugin Installation/Activation via Low Privilege User

Low privileged users can use the AJAX action 'cp_plugins_do_button_job_later_callback' in the WP Maintenance Mode & Site Under Construction WordPress plugin before 1.8.2, to install any plugin (including a specific version) from the WordPress repository, as well as activate arbitrary plugin from then blog, which helps attackers install vulnerable plugins and could lead to more critical vulnerabilities like RCE.