Disclaimer: This material is provided solely for educational purposes. You are fully responsible for how you use the information.
We do not encourage any kind of illegal or harmful activity.

1. General File Upload Testing

   • Upload files containing payloads and observe application response.
   • Attempt to change file paths to overwrite existing system files.
   • Test the application's handling of excessively large files to prevent Denial of Service attacks.
   • Check for leakage of metadata from uploaded files.
   • Assess vulnerabilities related to the ImageMagick library (e.g., Image Tragick - CVE-2016-3714).
   • Conduct pixel flood attacks with images of high density.
   • Verify file storage location for directory traversal vulnerabilities.
   • Ensure that proper validation of file types is enforced both client-side and server-side.
   • Test for server-side code execution vulnerabilities by uploading files with executable content.
   • Check if uploaded files are securely sandboxed to prevent unauthorized access.

2. Bypass Techniques

   • Test null byte (%00) bypass for file type checks.
   • Assess the enforcement of MIME types (Content-Type bypass).
   • Test file content checking based on header bytes (Magic Byte bypass).
   • Confirm server-side enforcement of file restrictions to bypass client-side validation.
   • Verify the robustness of file extension checks against blacklisted extensions.
   • Test for Unicode vulnerabilities in file names (homographic character bypass).
   • Attempt to bypass restrictions by using double file extensions (e.g., file.jpg.php).
   • Test file upload functionality in various contexts within the application.
   • Utilize automated tools and scripts for comprehensive file upload security testing.
   • Review the application's code for insecure handling practices related to file uploads.

3. Specific Attacks

   • Test for XXE (XML External Entity) injection via file upload.
   • Attempt to upload files with malicious content triggering SSRF (Server-Side Request Forgery).
   • Verify file handling in different environments (e.g., Windows vs. Linux).
   • Check for stored XSS vulnerabilities by uploading files with script content in metadata.
   • Test for insecure file upload configurations in third-party libraries or plugins.

4. Post-Upload Testing

   • Verify if uploaded files are scanned for malware.
   • Ensure uploaded files are stored in non-executable directories.
   • Implement proper access controls on uploaded files to prevent unauthorized access.
   • Test for race conditions in file upload functionality.