Executive Summary
Serverless means you don’t manage servers — but you still manage security. This guide explains the unique risks in AWS Lambda, Azure Functions, and Cloud Functions, plus how to lock down your serverless workloads.
Introduction
Serverless removes infrastructure management, but it also removes familiar security tools like firewalls or host antivirus. Many teams treat serverless as “set and forget” — leading to exposed environment variables, overly permissive roles, and vulnerable dependencies.
1. Top Serverless Risks
Table
| Risk | Explanation | Impact |
|---|---|---|
| Overly Permissive IAM Roles | Functions get more rights than needed | Full account takeover if compromised |
| Secrets in Environment Variables | Keys stored in plain settings | Credential theft in logs or dumps |
| Vulnerable Dependencies | Old libraries in function code | Remote code execution |
| Event Injection | Malicious data from APIs/SQS bypasses checks | Data corruption or unauthorized actions |
| No Visibility | Hard to track what runs and who calls it | Slow breach detection |
2. Best Practices
✅ Least Privilege Roles: Give only exactly what the function needs — never use AdministratorAccess
✅ Never store secrets in env vars: Use AWS Secrets Manager / Azure Key Vault / Cloud KMS instead
✅ Scan dependencies: Use Snyk or built-in scanning before deploy
✅ Validate ALL input: Reject unexpected size, format, or fields
✅ Short execution time: Set max timeout to stop abuse
✅ VPC when needed: Keep functions private if they don’t need public access
3. Provider-Specific Tips
- AWS Lambda: Use Resource Policies; enable DLQ for failures
- Azure Functions: Use Managed Identity; disable public access
- GCP Cloud Functions: Use VPC Connector; enforce HTTPS only
Conclusion
Serverless security is different but not harder — focus on identity, input validation, and secrets management. If you control these three, you block most attacks.
Tags: #ServerlessSecurity #AWSLambda #AzureFunctions #CloudSecurity