The ImageMagick Engine plugin for WordPress is vulnerable to remote code execution via the 'cli_path' parameter in versions up to, and including 1.7.5. This makes it possible for unauthenticated users to run arbitrary commands leading to remote command execution, granted they can trick a site administrator into performing an action such as clicking on a link. This makes it possible for an attacker to create and or modify files hosted on the server which can easily grant attackers backdoor access to the affected server.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.