Securing Serverless Functions

Securing Serverless Functions

Overview

Cybersecurity skill for securing serverless functions. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "securing serverless functions"

• "This skill covers security hardening for serverless compute platforms including "

• When deploying Lambda functions or Azure Functions with access to sensitive data or cloud APIs

• When auditing existing serverless workloads for overly permissive IAM roles

• When integrating serverless functions into a DevSecOps pipeline with automated security scanning

• When hardcoded secrets or vulnerable dependencies are discovered in function code

• When establishing runtime monitoring for serverless workloads to detect injection or credential theft

Do not use for container-based compute security (see securing-kubernetes-on-cloud), for API Gateway configuration (see implementing-cloud-waf-rules), or for serverless architecture design decisions.

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• AWS Lambda, Azure Functions, or GCP Cloud Functions with deployment access
• CI/CD pipeline with dependency scanning tools (npm audit, Snyk, Dependabot)
• AWS Secrets Manager, Azure Key Vault, or HashiCorp Vault for secrets management
• CloudWatch, Application Insights, or Cloud Logging for function monitoring

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}

1. Define Objectives — Clarify the goals and scope for serverless functions.
2. Gather Resources — Collect tools, data, and access needed for serverless functions.
3. Execute Process — Carry out serverless functions operations methodically.
4. Verify Quality — Check results against acceptance criteria.
5. Document Outcomes — Record findings, decisions, and next steps.

Tools

• Analysis Platform — Data processing and visualization
• Collaboration Tools — Team coordination and knowledge sharing

Process

1. Prepare — Gather requirements, verify prerequisites, set up environment
2. Execute — Run securing serverless functions workflow with configured parameters
3. Verify — Validate output meets requirements, document results

Verification

• All serverless functions procedures executed completely and documented
• Findings validated against multiple data sources
• False positives identified and filtered
• Results documented with evidence and timestamps
• Recommendations provided with risk-based prioritization

Anti-Rationalization Table