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March 9, 2026

Serverless Security Testing: Lambda, Functions, and Cloud Run

Viktor Bulanek
Founder & CTO, Penetrify
MSc IT Security · 20+ years in security · 4x Ex-CTO

Execution Role Testing

Every serverless function runs with an IAM role that defines what cloud resources it can access. Testing evaluates whether roles follow least-privilege, whether functions share roles (amplifying blast radius), and whether role permissions enable privilege escalation through service chaining.

Event Source Injection

Serverless functions are triggered by events-API Gateway requests, S3 uploads, SQS messages, CloudWatch events. Each event source is a potential injection vector. Testing evaluates input validation at the event source level, not just within the function code.

Environment Variables and Secrets

Functions frequently store configuration and secrets in environment variables-visible to anyone with function read access. Testing checks for plaintext secrets, sensitive configuration exposure, and whether functions use proper secrets management (Secrets Manager, Parameter Store, Key Vault) instead of environment variables.

Cold Start and Timeout Abuse

Serverless functions have execution time limits and cold start behaviours that create unique denial-of-service and timing attack vectors. Testing evaluates resource limits, concurrency settings, and whether timeout behaviours expose partial state.

Serverless Testing with Penetrify

Penetrify's serverless security testing covers Lambda, Azure Functions, and Cloud Functions with execution role analysis, event source injection testing, secrets management evaluation, and cross-service attack path assessment.

The Bottom Line

Serverless doesn't mean security-less. Functions inherit risk through their execution roles, event sources, and environment configurations. Penetrify tests all three layers.

Frequently Asked Questions

What's different about serverless security testing?Serverless eliminates OS-level concerns but amplifies IAM and configuration risks. Testing focuses on execution roles, event source injection, secrets management, and cross-service privilege escalation. Can I use traditional pentesting tools for serverless?Traditional network and web application tools miss most serverless-specific risks. Serverless testing requires cloud-native tools and methodology focused on IAM, event-driven architecture, and service integration.

Frequently Asked Questions

What types of vulnerabilities does Penetrify detect?

Penetrify detects all OWASP Top 10 vulnerability categories including SQL injection, XSS, CSRF, IDOR, broken authentication, security misconfigurations, and sensitive data exposure. It also tests API security, session management, and common misconfigurations in Supabase, Firebase, and Bubble.

How long does an AI penetration test take?

A quick scan completes in 15–30 minutes. A standard scan runs 1–2 hours with broader coverage. A deep scan can run several hours for complex applications.

What does a Penetrify report include?

Every report includes an executive summary, overall security score, severity-classified findings (Critical, High, Medium, Low), step-by-step reproduction steps, and concrete remediation guidance written for developers — not compliance officers.

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