CMP < 4.1.17 - Admin+ Arbitrary File Upload and Remote Code Execution

Description

The plugin is vulnerable to arbitrary file upload and remote code execution 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.