# Web Application Penetration Testing Methodology: OWASP WSTG, PTES, NIST SP 800-115

**URL:** https://securesys.com.tr/en/learning/web-application-security/web-application-penetration-testing-methodology

### Why Is a Methodology Needed?

![Web application penetration testing methodology: OWASP WSTG, PTES, NIST SP 800-115](/images/bilgi-merkezi/covers/cover-metodoloji.webp)

A penetration test performed on a web application is not merely a matter of running security tools. When two different experts assess the same application, they can reach very different results if the methods used differ. A successful penetration test must therefore be based on a systematic, repeatable methodology aligned with international standards.

At SecureSys, we handle every web application penetration test within a defined plan: information gathering, identifying the attack surface, manual analysis, verification work, risk assessment and reporting.

### International Standards

- **OWASP Web Security Testing Guide (WSTG)** — a comprehensive control framework for security testing of web applications.
- **OWASP Top 10** — the reference for the most critical web application security risks.
- **PTES (Penetration Testing Execution Standard)** — a methodology that defines the penetration-testing life cycle.
- **NIST SP 800-115** — a guide for technical security assessments of information systems.
- **CVSS v4.0** — the standard used to score the technical risk of the vulnerabilities found.

### The Web Application Penetration Testing Life Cycle

Planning → Information Gathering (Reconnaissance) → Attack Surface Analysis → Automated Security Scanning → Manual Security Testing → Business Logic Analysis → Risk Verification → CVSS Risk Assessment → Preparation of Technical and Executive Reports → Post-Remediation Verification (Re-Test)

#### \1. Planning and Scope Definition

The boundaries of the test, target systems, critical business processes and the communication plan are clarified: Which domains will be tested? Are APIs in scope? Will the test be conducted with a Black Box, Gray Box or White Box approach?

#### \2. Information Gathering (Reconnaissance)

Subdomains, open services, HTTP headers, certificates, JavaScript files, API endpoints and the technology stack (framework, CMS, server) are examined.

#### \3. Attack Surface Mapping

Login screens, registration forms, file-upload modules, management panels, API services and user roles are mapped in detail.

#### \4. Automated Security Scanning

Known vulnerabilities, security headers, misconfigurations and TLS/SSL configurations are scanned quickly. Automated scanning does not replace experts, but it helps determine where manual analysis should focus.

#### \5. Manual Security Testing

The most important stage of the SecureSys approach. Our experts test [authorization controls](/en/learning/web-application-security/broken-access-control-idor-bola), [authentication processes](/en/learning/web-application-security/authentication-session-management-security-mfa), [business logic](/en/learning/web-application-security/business-logic-security-vulnerabilities) and [API behaviour](/en/learning/web-application-security/api-security-owasp-api-security-top-10) manually, from the perspective of a real attacker.

#### \6. Risk Analysis and Prioritisation

Every finding is evaluated against criteria such as exploitability, business impact, data sensitivity, privilege requirement and detectability.

#### \7. Technical Reporting and Executive Summary

For every finding, a description, technical details, proof of concept (PoC), risk level and remediation recommendations are reported; a summary for senior management is also prepared without overwhelming technical detail. See our [deliverables](/en/learning/web-application-security/penetration-testing-deliverables-reporting) page for details.

#### \8. Remediation Verification (Re-Test)

After the organisation's remediation work, the relevant findings are re-tested and verified. The re-test is not the end of the process but part of a continuous improvement cycle.

### Assessment Criteria

| Assessment Criterion | Description |
| --- | --- |
| Exploitability | How easy is the vulnerability to exploit? |
| Business Impact | Which processes does the vulnerability affect? |
| Data Sensitivity | Which data is at risk? |
| Privilege Requirement | Does the attacker need prior privileges? |
| Detectability | Is exploitation of the vulnerability easily noticed? |

To have your web application tested with a methodology aligned to international standards, reach out via our [Web Application Penetration Testing Service](/en/services/web-application-security-test-service) page.