Web Application Methodology

OWASP Testing Guide Approach

The OWASP Web Security Testing Guide (WSTG) serves as an industry-standard reference for vulnerability coverage. Rather than dictating workflow, OWASP provides a checklist to ensure nothing is missed during testing.

OWASP Testing Categories Reference

The OWASP WSTG v4.2 organizes security tests into these categories:

• Information Gathering (WSTG-INFO): Map scope, endpoints, frameworks and attack surface.

• Configuration Management (WSTG-CONF): Identify misconfigurations in servers, frameworks and cloud services.

• Identity & Authentication (WSTG-IDNT / WSTG-ATHN): Test authentication flows, credential management and MFA.

• Authorization (WSTG-ATHZ): Validate access control, horizontal/vertical privilege separation and IDORs.

• Session Management (WSTG-SESS): Evaluate session token handling, fixation, CSRF and expiry.

• Input Validation (WSTG-INPV): Test for XSS, SQLi, command injection, template injection and request smuggling.

• Error Handling (WSTG-ERRH): Identify information leakage from stack traces and error messages.

• Cryptography (WSTG-CRYP): Verify TLS configuration, certificate validation and secure storage practices.

• Business Logic (WSTG-BUSL): Assess workflow integrity, abuse cases and process assumptions.

• Client-Side Testing (WSTG-CLNT): Test DOM XSS, CORS, client resource manipulation and clickjacking.

• API Testing (WSTG-APIT): Evaluate REST/GraphQL endpoints, authentication, authorization and rate limits.

Key Insight: OWASP provides the what to test, but your workflow determines when and how to test efficiently.

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Web Application Architecture

Modern Architecture Assessment

Understanding an application’s architecture is essential to identify attack vectors and define effective testing strategies.

Architecture Analysis Framework

Technology Stack Identification

• Frontend: JavaScript frameworks (React, Angular, Vue), CSS frameworks, build tools, bundlers, and CDNs ⇒ focus on client-side vulnerabilities.

• Backend: Web servers (Apache, Nginx, IIS), app frameworks, databases, caching ⇒ reveals server-side risks and escalation paths.

• Tools: Wappalyzer, WhatWeb, Nuclei templates, and manual header analysis.

Application Topology Mapping

• Objectives: Identify entry points, APIs, integrations, database connections, and external services.

• Patterns: Monolith, microservices, serverless, SPAs ⇒ each requires tailored testing.

• Documentation: Diagrams of data flows, trust boundaries, and dependencies to highlight attack paths.

Security Control Identification

• WAFs: Detect, fingerprint, analyze rules, and assess rate limiting.

• Authentication: SSO, MFA, session management, API auth ⇒ each introduces unique bypass possibilities.

• Security Headers: CSP, HSTS, CORS, etc., provide insights into protection layers.

Architecture-Specific Testing Considerations

• SPAs: Test APIs, token handling, and client-side security.

• Microservices: Assess API gateways, inter-service auth, and communication.

• Cloud-Native: Evaluate container security, serverless risks, and cloud misconfigurations.