Betheme <= 28.4 - Authenticated (Contributor+) Arbitrary File Deletion via 'mfn-icon-upload'

The Betheme theme for WordPress is vulnerable to Arbitrary File Deletion in versions up to, and including, 28.4. This is due to the upload_icons() function workflow using a user-controlled upload path (`mfn-icon-upload`) in a filesystem move operation without constraining it to the uploads directory. This makes it possible for authenticated attackers, with contributor-level access and above, to move/delete arbitrary local files via path traversal.