For developers looking to secure their applications, resources like the OWASP File Upload Cheat Sheet provide detailed implementation guides. Additionally, penetration testing tools are often used to simulate "gunner" style attacks to identify bypass techniques that could be used by malicious actors. File uploads | Web Security Academy - PortSwigger
Large files can be used to perform Denial of Service (DoS) attacks by exhausting server storage or memory. "Hot" Strategies for Securing File Uploads
Only allow a strictly defined list of safe file extensions. fileupload gunner project hot
To mitigate these risks, the project and industry leaders like the OWASP Foundation recommend several "hot" mitigation strategies:
Do not trust the Content-Type header, as it can be spoofed; instead, inspect the actual file contents to verify its type. "Hot" Strategies for Securing File Uploads Only allow
Attackers can upload malicious scripts (like web shells) that execute on the server, potentially leading to a complete system takeover.
Set strict maximums for both filename length and overall file size. Set strict maximums for both filename length and
Uploaded files may contain code designed to infect the system or other users.
