What Is Penetration Testing?
Penetration testing (pentesting) is an authorized, controlled attempt to exploit vulnerabilities in an organization's systems. Unlike vulnerability scanning, which identifies potential weaknesses, penetration testing actively exploits them to demonstrate real-world risk and impact.
Types of Penetration Testing
| Type | Scope | Focus | |---|---|---| | Network pentest | Internal/external network | Firewalls, servers, network services | | Web application pentest | Web apps and APIs | OWASP Top 10, business logic flaws | | Cloud pentest | Cloud infrastructure | Misconfigurations, IAM weaknesses | | Social engineering | Human element | Phishing, pretexting, physical access | | Red team engagement | Full organization | Multi-vector, simulating real adversaries | | Purple team exercise | Collaborative | Red team attacks while blue team defends |
Pentest Methodology
Most penetration tests follow a standard methodology:
- Scoping: Define targets, rules of engagement, and goals
- Reconnaissance: Gather information about the target (OSINT, network scanning)
- Vulnerability Analysis: Identify potential vulnerabilities
- Exploitation: Attempt to exploit identified vulnerabilities
- Post-Exploitation: Determine impact — data access, lateral movement, privilege escalation
- Reporting: Document findings with evidence, risk ratings, and remediation guidance
Black Box vs. White Box vs. Gray Box
| Approach | Tester Knowledge | Simulates | |---|---|---| | Black box | No prior knowledge | External attacker | | White box | Full access (source code, architecture) | Insider threat, deep assessment | | Gray box | Partial knowledge (credentials, architecture) | Compromised user, most realistic |
Pentest vs. Vulnerability Scan vs. Red Team
- Vulnerability scan: Automated, identifies known vulnerabilities, no exploitation
- Penetration test: Manual + automated, exploits vulnerabilities, proves impact
- Red team: Extended engagement, simulates real adversary TTPs, tests detection and response
When to Pentest
- Before launching new applications or major features
- After significant infrastructure changes
- Annually (or more frequently) for compliance (PCI DSS requires annual pentests)
- After a security incident to validate remediation