AWS Security Testing: A Practitioner's Guide to Pentesting Amazon Web Services

IAM: The Crown Jewels

AWS IAM is the most powerful—and most commonly misconfigured—service in the entire ecosystem. Testing must evaluate IAM policies for least-privilege violations, identify unused roles and access keys, probe for privilege escalation paths (role chaining, policy attachment, AssumeRole abuse), test Service Control Policies for enforcement effectiveness, and verify that cross-account access is properly constrained. A single overpermissive Lambda execution role can give an attacker access to every S3 bucket, every DynamoDB table, and every secret in Secrets Manager. IAM testing is where the highest-impact findings live.

S3 and Storage Security

S3 misconfigurations have been behind some of the largest data breaches in history. Testing covers bucket policies and ACLs for unintended public access, server-side encryption at rest, access logging and monitoring, versioning and lifecycle policies, and presigned URL generation for time-limited access. The 2023 Block Public Access defaults have improved baseline security, but legacy buckets and explicit policy overrides still create exposure.

Lambda and Serverless

Lambda functions introduce unique attack vectors: overpermissive execution roles that grant more access than the function needs, environment variables storing secrets in plaintext, event injection through unsanitised input from API Gateway or S3 triggers, and cold start timing attacks. Testing serverless requires understanding how event-driven architectures can be abused.

EC2, VPC, and Network Layer

EC2 testing evaluates security groups for overly permissive ingress rules, instance metadata service (IMDSv1 vs v2) configuration, EBS volume encryption, and SSH key management. VPC testing verifies that network ACLs and security groups implement proper segmentation, that VPC endpoints are configured for private service access, and that VPC peering doesn't create unintended cross-network paths.

Cross-Service Attack Paths

The most impactful AWS findings chain vulnerabilities across services. An SSRF in a web application retrieves temporary credentials from the EC2 metadata service (IMDSv1). Those credentials belong to an overpermissive role that can read secrets from Secrets Manager. The secrets include database credentials for the RDS instance containing customer data. This chain—web app → metadata → IAM → secrets → database—is exactly what skilled cloud pentesters look for and what automated scanners miss.

Testing AWS with Penetrify

Penetrify's AWS security testing covers IAM policy analysis, S3/storage security, Lambda and serverless configurations, EC2/VPC network architecture, and cross-service attack path validation. Practitioners hold AWS security certifications and understand the provider-specific nuances that generic pentesters miss. Compliance-mapped reports serve SOC 2, PCI DSS, HIPAA, and ISO 27001 auditors.