Web

Introduction to File Upload Attacks File upload features are extremely common in web apps, from profile pictures to document portals. The moment an app stores user-controlled files on the server, it expands the attack surface beyond standard input fields. If validation is weak or missing, attackers can upload active content and trigger code execution. The core risk is that a server may treat an uploaded file as code rather than data. That can happen when the extension is executable, the server is misconfigured, or the upload directory allows script execution. Even if direct execution is blocked, uploads can enable stored XSS, XXE, or DoS. ...