Xerte Online Toolkits <= 3.14 Unauthenticated Template Import Arbitrary File Upload Leading to Remote Code Execution

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.