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March 9, 2026

Cloud Network Security Testing: VPCs, Security Groups, and Firewall Rules

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

Security Group and NSG Testing

Testing evaluates every security group/NSG rule for overpermissive access-especially inbound rules that allow broad IP ranges, port ranges, or protocol wildcards. Stale rules, temporary exceptions that became permanent, and self-referencing groups that allow unrestricted intra-group communication all represent risk.

Network Segmentation Validation

Testing verifies that network segmentation actually isolates what it's supposed to isolate. Can a workload in the development VPC reach production databases? Can a compromised web server access the management network? Segmentation testing proves your network boundaries hold under adversarial conditions-essential for PCI DSS compliance.

Egress Control Testing

Most cloud security testing focuses on inbound access. Egress testing evaluates whether outbound traffic is properly restricted-preventing data exfiltration, command-and-control communication, and lateral movement through unrestricted outbound access.

Cross-Cloud and Hybrid Connectivity

Testing evaluates VPN connections, VPC peering, PrivateLink/Private Endpoints, and transit gateways for unintended cross-network access paths.

Cloud Network Testing with Penetrify

Penetrify's cloud network testing covers security groups, NACLs, firewall rules, segmentation validation, and cross-network connectivity across AWS, Azure, and GCP.

The Bottom Line

Cloud network misconfigurations are invisible until an attacker exploits them. Penetrify tests every layer of your cloud networking-security groups, segmentation, egress controls, and cross-cloud connectivity.

Frequently Asked Questions

How do I test cloud network security?Evaluate security group/NSG rules for overpermissive access, validate network segmentation between environments, test egress controls, and verify cross-cloud connectivity restrictions. Combine automated configuration scanning with manual penetration testing for complete coverage.

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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