The Login as User or Customer WordPress plugin before 3.3 lacks authorization checks to ensure that users are allowed to log in as another one, which could allow unauthenticated attackers to obtain a valid admin session.
Low privileged users can use the AJAX action 'cp_plugins_do_button_job_later_callback' in the Login as User or Customer (User Switching) WordPress plugin before 1.8, 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.