What is Serverless Security?

Serverless security addresses the unique threats facing functions-as-a-service platforms like AWS Lambda, including overprivileged functions, injection attacks, and insecure dependencies.

What is serverless security?

Serverless security addresses threats specific to functions-as-a-service (FaaS) platforms like AWS Lambda, Azure Functions, and Google Cloud Functions. While cloud providers manage server infrastructure, developers remain responsible for function code security, IAM permissions, dependency management, data protection, and secure event trigger configurations.

What are the main serverless security risks?

Key risks include overprivileged function execution roles, injection attacks through event data, vulnerable third-party dependencies, insecure function configurations, data exposure through environment variables, insufficient logging and monitoring, event data injection from untrusted triggers, and denial-of-wallet attacks from recursive or amplified invocations.

How does serverless change the security model?

Serverless shifts infrastructure security responsibility to cloud providers but expands the application security surface. Each function is an independent attack surface with its own IAM role, dependencies, and event triggers. The ephemeral nature limits persistent threats but complicates traditional security monitoring and forensic analysis.

How do you secure serverless function permissions?

Apply least-privilege IAM policies granting each function only the specific permissions it needs. Avoid wildcard resource permissions, use separate roles per function rather than shared roles, implement resource-based policies where possible, and regularly audit function permissions for privilege creep using tools like IAM Access Analyzer.

What is event injection in serverless?

Event injection occurs when attackers craft malicious event data (from API Gateway, S3 events, SQS messages, or other triggers) to exploit vulnerabilities in function code. This can lead to command injection, SQL injection, or SSRF if functions process event data without proper validation and sanitization of all input fields.

How do you monitor serverless applications?

Monitor serverless applications using cloud-native tools like AWS CloudWatch and X-Ray, implement structured logging within functions, use serverless-aware security tools that understand function invocation patterns, set up anomaly detection for unusual invocation rates or duration, and aggregate logs into SIEM platforms for correlation.

What are serverless security testing approaches?

Testing approaches include SAST scanning of function code, SCA for dependency vulnerabilities, DAST against API Gateway endpoints, IAM policy analysis for overprivileged roles, configuration review of function settings, event injection testing with malicious payloads, and runtime behavior analysis during functional testing.

What is a denial-of-wallet attack?

A denial-of-wallet attack exploits serverless auto-scaling by triggering massive numbers of function invocations to inflate cloud costs. Recursive function calls, event loop amplification, or external traffic floods can cause runaway costs. Prevention requires concurrency limits, budget alarms, dead-letter queues, and rate limiting on triggers.