Malicious File Upload

Summary

Malicious File Upload is an application attack where attackers upload harmful files to a target system, enabling unauthorized access, code execution, or data compromise.

Key Characteristics

• Exploitation of file upload functionalities in web applications.
• Upload of executable files, scripts, or malware disguised as legitimate files.
• Potential to execute arbitrary code on the server or client side.
• Bypassing file type and size restrictions through obfuscation techniques.
• Use in establishing backdoors, defacing websites, or stealing sensitive data.

Defensive Controls

• Implement strict server-side validation of file types and content.
• Use allowlists for permitted file extensions and MIME types.
• Scan uploaded files with antivirus and malware detection tools.
• Store uploaded files outside the webroot to prevent direct execution.
• Apply least privilege principles to file storage and execution permissions.
• Employ web application firewalls (WAF) to detect and block malicious payloads.

Related Security Solutions

Web Application Firewalls (WAF), Antivirus and Anti-malware software, Secure File Upload Libraries, Content Security Policy (CSP), Intrusion Detection and Prevention Systems (IDPS), and Runtime Application Self-Protection (RASP) tools are commonly used to mitigate malicious file upload attacks.