Serverless Function Injection

HighCloud SecurityOWASP Serverless Top 10

Serverless functions (AWS Lambda, Azure Functions, Google Cloud Functions) process untrusted input without proper validation, enabling injection attacks, unauthorized data access, and abuse of excessive function permissions to compromise cloud resources.

Immediate Response

1Restrict the serverless function's IAM role to minimum required permissions immediately.
2Add input validation and sanitization to all event data processed by the function.
3Review function execution logs for evidence of data exfiltration or unauthorized access.
4Disable or throttle the function if active exploitation is detected.

All playbooks

1Implement strict input validation schemas for all serverless function event inputs.
2Apply least-privilege IAM roles with resource-level permissions for each function.
3Enable function execution logging and forward logs to a SIEM for monitoring.
4Scan serverless function dependencies for known vulnerabilities before deployment.

Long-term Prevention

1Implement serverless-specific security scanning in CI/CD pipelines.
2Deploy serverless security platforms for runtime protection and anomaly detection.
3Use infrastructure-as-code to enforce serverless security policies and IAM guardrails.
4Conduct regular serverless architecture threat modeling and penetration tests.

Attack vectors

Injection payloads in event source data (API Gateway, S3 events, SQS messages) processed by functions
Serverless functions with overly permissive IAM roles accessing unrelated cloud resources
Deserialization of untrusted event payloads triggering code execution
Dependency vulnerabilities in serverless function code or layers

Indicators of compromise

Serverless function invocations with unexpected input patterns or injection payloads in event data
Function execution logs showing access to cloud resources outside the function's intended scope
Anomalous function execution duration, memory usage, or invocation frequency
Cloud audit logs showing serverless function roles accessing unauthorized resources

Tooling

AWS Lambda Power TuningSnykPureSec (Serverless Security)ProtegoCheckov