Inisev Plugins (Various Versions) - Cross-Site Request Forgery on handle_installation function

Several plugins for WordPress by Inisev are vulnerable to Cross-Site Request Forgery to unauthorized installation of plugins due to a missing nonce check on the handle_installation function that is called via the inisev_installation AJAX aciton in various versions. This makes it possible for unauthenticated attackers to install plugins from the limited list via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.