Xerte Online Toolkits versions 3.14 and earlier contain an unauthenticated arbitrary file upload vulnerability in the template import functionality that allows remote attackers to execute arbitrary code by uploading a crafted ZIP archive containing malicious PHP payloads. Attackers can bypass authentication checks in the import.php file to upload a template archive with PHP code in the media directory, which gets extracted to a web-accessible path where the malicious PHP can be directly accessed and executed under the web server context.