Arbitrary File Upload in user_payment_update.php in SourceCodester Client Database Management System 1.0 allows unauthenticated users to upload arbitrary files via the uploaded_file_cancelled field. Due to the absence of proper file extension checks, MIME type validation, and authentication, attackers can upload executable PHP files to a web-accessible directory (/files/). This allows them to execute arbitrary commands remotely by accessing the uploaded script, resulting in full Remote Code Execution (RCE) without authentication.
SourceCodester Client Database Management System 1.0 is vulnerable to Remote code execution via Arbitrary file upload in user_proposal_update_order.php.