Securing Amazon S3 presigned URLs for serverless applications

This article provides comprehensive guidance on securing Amazon S3 presigned URLs in serverless applications, highlighting five key security strategies:

• Add Content-MD5 checksum to ensure data integrity and prevent unauthorized file uploads
• Implement dynamic URL expiration based on file size and network type
• Generate unique UUIDs to replace original filenames and prevent path traversal attacks
• Apply the Principle of Least Privilege by creating dedicated Lambda functions with minimal S3 permissions
• Create one-time use presigned URLs with token-based validation mechanisms

The article emphasizes the importance of implementing multiple security layers to protect serverless applications when using S3 presigned URLs, ensuring secure and controlled file uploads.