Exploiting File Upload Vulnerabilities: A Guide for Bug Bounty Hunters

On April 11, 2026, two articles were published detailing methodologies for exploiting file upload vulnerabilities in web applications. These vulnerabilities can lead to severe attacks such as Remote Code Execution (RCE), Cross-Site Scripting (XSS), and path traversal overwrites. The articles emphasize that every file upload feature presents a potential attack surface, especially if misconfigured. They provide a comprehensive guide for security testers on how to approach file uploads, focusing on both the content of the files and the request parameters. The techniques discussed include basic extension tricks and advanced out-of-band RCE methods. This information is crucial for cybersecurity professionals engaged in bug bounty programs. The articles do not mention specific CVEs or tools but highlight the importance of thorough testing in identifying vulnerabilities.

Key Points: • File upload features are common attack vectors in web applications. • Misconfigured uploaders can lead to serious vulnerabilities like RCE and XSS. • The articles provide methodologies for testing file uploads effectively.