The CMP – Coming Soon & Maintenance Plugin by NiteoThemes plugin for WordPress is vulnerable to arbitrary file upload and remote code execution in all versions up to, and including, 4.1.16 via the cmp_theme_update_install AJAX action. This is due to the function only checking for the publish_pages capability (available to Editors and above) instead of manage_options (Administrators only), combined with a lack of proper validation on the user-supplied file URL and no verification of the downloaded file's content before extraction. This makes it possible for authenticated attackers, with Administrator-level access and above, to force the server to download and extract a malicious ZIP file from a remote attacker-controlled URL into a web-accessible directory (wp-content/plugins/cmp-premium-themes/), resulting in remote code execution. Due to the lack of a nonce for Editors, they are unable to exploit this vulnerability.