Penetration testing methodologies

Penetration testing (pentesting) methodologies are structured frameworks used by security professionals to simulate cyberattacks. These frameworks ensure that tests are consistent, repeatable, and thorough—moving beyond simple automated scanning to deep manual exploitation.

As of 2025, the industry relies on five primary methodologies, each suited for different environments and compliance needs.

1. Top Industry Standards & Frameworks

Methodology	Best For…	Key Focus
OWASP WSTG	Web Applications	Testing for the “Top 10” risks (Injection, XSS, Broken Access Control).
PTES	Comprehensive Audits	A highly technical, practitioner-focused lifecycle from scoping to post-exploitation.
NIST SP 800-115	Compliance & Govt	A formal, structured guide often used for federal and enterprise regulatory audits.
OSSTMM	Holistic/Scientific	Focuses on operational security across human, physical, and wireless channels.
ISSAF	Infrastructure	Deep dive into specialized systems like mainframes, routers, and legacy hardware.

2. The Standard Pentest Lifecycle (PTES-aligned)

While frameworks vary, most follow a core 5-to-7 phase process.

Pre-engagement & Scoping: Defining the “Rules of Engagement” (RoE). This establishes what is off-limits, the testing window, and legal permissions.
Intelligence Gathering (Reconnaissance): Collecting data about the target using OSINT (Open Source Intelligence).
- Passive: Searching public records and social media.
- Active: Direct interaction like port scanning and DNS interrogation.
Vulnerability Analysis: Analyzing gathered data to identify potential entry points and security flaws.
Exploitation: The “hack” itself. Testers attempt to bypass security controls to gain access, proving that a vulnerability isn’t just theoretical but practical.
Post-Exploitation: Determining the value of the machine or data compromised. This includes Privilege Escalation (gaining admin rights) and Lateral Movement (moving through the network).
Reporting: The final deliverable. It translates technical findings into business risks and provides remediation steps for developers and IT teams.

3. Testing Approaches (The “Boxes”)

Methodologies are further categorized by how much “insider information” the tester is given before starting.

Black Box: The tester has zero prior knowledge. This mimics an external hacker starting from scratch.
White Box: The tester has full access (source code, network diagrams, admin credentials). This is the most thorough and time-efficient for identifying deep logic flaws.
Grey Box: The tester has limited information (e.g., a standard user login). This is the most common approach as it simulates an “insider threat” or a hacker who has already gained a foothold.

4. Modern Trends (2025)

Threat-Informed Testing: Using the MITRE ATT&CK framework to map pentest activities to real-world tactics used by known threat actors.
AI-Augmented Pentesting: Using tools like PentestGPT or autonomous agents to speed up reconnaissance and basic vulnerability discovery.
Purple Teaming: A collaborative approach where the attackers (Red Team) and defenders (Blue Team) work together in real-time to test and improve detection capabilities simultaneously.

Would you like me to dive deeper into a specific framework like OWASP for web apps, or perhaps look at the Rules of Engagement document structure?

5. OSSTMM (Open Source Security Testing Methodology Manual)

Focus: Scientific measurement of security through operational security testing.
Domains: Physical security, wireless, telecommunications, human psychology, and data networks.
Strengths: Quantitative, evidence-based, and vendor-neutral.
Use Case: Comprehensive security audits across physical and digital domains.

6. PTES (Penetration Testing Execution Standard)

Seven Phases:
1. Pre-engagement Interactions – Define scope, rules of engagement, and NDA.
2. Intelligence Gathering – Passive/active reconnaissance (e.g., WHOIS, DNS, OSINT).
3. Threat Modeling – Identify high-value targets and potential attack vectors.
4. Vulnerability Analysis – Scan and validate weaknesses (e.g., using Nessus, Nmap).
5. Exploitation – Gain access (e.g., via Metasploit, custom payloads).
6. Post-Exploitation – Maintain access, pivot, and assess impact.
7. Reporting – Document findings, risk ratings, and remediation steps.
Strengths: Clear, phase-based, and widely adopted in professional engagements.

7. OWASP Testing Guide (for Web & API Security)

Focus: Application-layer security (web apps, APIs, mobile backends).
Key Areas:
- Authentication/Authorization flaws
- Input validation (e.g., XSS, SQLi)
- Business logic abuse
- API security (broken object-level authorization, excessive data exposure)
Aligned With: OWASP Top 10, ASVS (Application Security Verification Standard).
Tools: Burp Suite, ZAP, sqlmap.
Use Case: Essential for modern web and API penetration testing.

8. NIST SP 800-115 (Technical Guide to Information Security Testing)

Framework:
- Planning – Define objectives and scope.
- Discovery – Identify systems and services.
- Vulnerability Scanning – Automated detection.
- Penetration Testing – Manual exploitation.
- Reporting & Remediation.
Strengths: Government and compliance-friendly (e.g., FedRAMP, HIPAA).
Use Case: Regulated industries and U.S. federal systems.

9. CREST & CHECK (UK-Centric, but influential globally)

CREST: Defines standards for professional penetration testers (e.g., CRT, CCT certifications).
CHECK: UK government scheme for testing classified systems.
Strengths: Emphasis on tester qualifications and legal compliance.

Choosing the Right Methodology

Scenario	Recommended Methodology
Web/API app testing	OWASP Testing Guide + PTES
Full infrastructure audit	PTES + NIST SP 800-115
Compliance-driven (e.g., PCI DSS)	PTES + NIST
Red teaming / advanced simulation	PTES + MITRE ATT&CK (for adversary emulation)

Best Practices

Always obtain written authorization.
Define a clear scope (in-scope/out-of-scope assets).
Use ethical and legal boundaries (no data destruction/exfiltration without consent).
Combine automated scanning (e.g., Nessus, Nikto) with manual testing for depth.
Deliver actionable reports with CVSS scores, PoC, and remediation guidance.

Recommended Methodology: Hybrid (PTES + OWASP)

Use PTES for structure and OWASP Testing Guide v4/v5 for application/API-specific depth.

🔍 Phase-by-Phase Plan

1. Pre-Engagement & Scoping (Already Done)

Environments: Dev & Test only (clearly isolated from Prod)
Out of Scope: Production systems, third-party services (unless integrated)
Rules of Engagement: No destructive payloads; avoid DoS; no real user data exfiltration

2. Reconnaissance & Mapping

For Web Apps / APIs:
- Enumerate all endpoints via:
  - Proxy tools (Burp Suite, OWASP ZAP)
  - API documentation (Swagger/OpenAPI)
  - Automated crawlers (gau, waybackurls, ffuf)
- Identify tech stack (Wappalyzer, builtwith, HTTP headers)
For Internal/Test Networks (if applicable):
- Network scanning (nmap -sV -sC -p-)
- Service enumeration (SMB, SSH, databases, etc.)

3. Threat Modeling (Focus on Your Concerns)

Prioritize testing for:

Authentication Bypass
- Missing auth on sensitive endpoints
- Weak session handling (predictable tokens, no expiration)
- Direct object references (IDOR)
Data Leakage
- Verbose error messages (stack traces, DB dumps)
- Sensitive data in logs, URLs, or responses (API keys, PII)
- Insecure caching or CORS misconfigurations
Privilege Escalation
- Horizontal (user A accesses user B’s data)
- Vertical (regular user → admin via role manipulation)
- Insecure direct object references (IDOR) in APIs
- JWT tampering or role claim modification

4. Vulnerability Analysis & Exploitation

Use targeted checks:

Concern	Test Techniques	Tools
Auth Bypass	Access `/admin` without login; replay requests with altered cookies/tokens; test for JWT `alg: none`	Burp Suite, jwt_tool, Postman
Data Leakage	Fuzz parameters for unexpected data; check debug modes; test for excessive API responses	Burp Scanner, `grep` logs, ZAP
Privilege Escalation	Create 2 test accounts (user/admin); replay user requests with admin cookies/roles; manipulate `user_id` or `role` in JSON/body/headers	Burp Repeater, Intruder

💡 Critical Dev/Test Pitfalls to Check:

Hardcoded credentials in config files or source code (use truffleHog or gitleaks if source access is allowed)

Over-permissive API keys in test environments

Debug/developer endpoints left enabled (/actuator, /debug, /phpinfo)

Disabled security controls (e.g., MFA, WAF, input validation)

5. Post-Exploitation (Safe & Limited)

Do NOT exfiltrate data—even if it’s “test” data (could contain real PII or secrets)
Document proof-of-concept (PoC) steps only (e.g., “Changed role=user to role=admin → gained admin access”)
Test impact (e.g., “Can delete other users’ records”)

6. Reporting

Structure findings by risk (use CVSS or OWASP Risk Rating):

High: Auth bypass leading to full account takeover
Medium: IDOR allowing access to other test users’ data
Low: Verbose error revealing framework version

Include:

Clear reproduction steps
Remediation advice (e.g., “Enforce server-side role checks”, “Sanitize API responses”)
References (OWASP ASVS, CWE)

🛠️ Tool Stack Suggestion

Proxy/Manual Testing: Burp Suite Community/Pro (or OWASP ZAP)
API Testing: Postman + Burp + ffuf for fuzzing
Auth Testing: jwt_tool, Burp’s “Engagement tools” for session analysis
Static Analysis (if source access): Semgrep, Bandit (Python), or SonarQube
Secrets Scanning: gitleaks, truffleHog (if testing includes repos)

⚠️ Reminder

Even in Dev/Test, always:

Avoid disruptive actions (e.g., filling DBs, triggering alerts)
Assume test data may accidentally contain real credentials or PII
Coordinate with DevOps to prevent breaking CI/CD pipelines