Security Penetration Testing

Hands-on offensive security testing skill for finding vulnerabilities before attackers do. This is NOT compliance checking (see senior-secops) or security policy writing (see senior-security) — this is about systematic vulnerability discovery through authorized testing.

Table of Contents

• Overview
• OWASP Top 10 Systematic Audit
• Static Analysis
• Dependency Vulnerability Scanning
• Secret Scanning
• API Security Testing
• Web Vulnerability Testing
• Infrastructure Security
• Pen Test Report Generation
• Responsible Disclosure Workflow
• Workflows
• Anti-Patterns
• Cross-References

Overview

What This Skill Does

This skill provides the methodology, checklists, and automation for offensive security testing — actively probing systems to discover exploitable vulnerabilities. It covers web applications, APIs, infrastructure, and supply chain security.

Distinction from Other Security Skills

Prerequisites

All testing described here assumes written authorization from the system owner. Unauthorized testing is illegal under the CFAA and equivalent laws worldwide. Always obtain a signed scope-of-work or rules-of-engagement document before starting.

OWASP Top 10 Systematic Audit

Use the vulnerability scanner tool for automated checklist generation:

# Generate OWASP checklist for a web application
python scripts/vulnerability_scanner.py --target web --scope full

# Quick API-focused scan
python scripts/vulnerability_scanner.py --target api --scope quick --json

Quick Reference

# Audit dependencies
python scripts/dependency_auditor.py --file package.json --severity high
python scripts/dependency_auditor.py --file requirements.txt --json

See owasp_top_10_checklist.md for detailed test procedures, code patterns to detect, remediation steps, and CVSS scoring guidance for each category.

Static Analysis

Recommended tools: CodeQL (custom queries for project-specific patterns), Semgrep (rule-based scanning with auto-fix), ESLint security plugins (eslint-plugin-security, eslint-plugin-no-unsanitized).

Key patterns to detect: SQL injection via string concatenation, hardcoded JWT secrets, unsafe YAML/pickle deserialization, missing security middleware (e.g., Express without Helmet).

See attack_patterns.md for code patterns and detection payloads across injection types.

Dependency Vulnerability Scanning

Ecosystem commands: npm audit, pip audit, govulncheck ./..., bundle audit check

CVE Triage Workflow:

1. Collect — Run ecosystem audit tools, aggregate findings
2. Deduplicate — Group by CVE ID across direct and transitive deps
3. Prioritize — Critical + exploitable + reachable = fix immediately
4. Remediate — Upgrade, patch, or mitigate with compensating controls
5. Verify — Rerun audit to confirm fix, update lock files

python scripts/dependency_auditor.py --file package.json --severity critical --json

Secret Scanning

Tools: TruffleHog (git history + filesystem), Gitleaks (regex-based with custom rules).

# Scan git history for verified secrets
trufflehog git file://. --only-verified --json

# Scan filesystem
trufflehog filesystem . --json

Integration points: Pre-commit hooks (gitleaks, trufflehog), CI/CD gates (GitHub Actions with trufflesecurity/trufflehog@main). Configure .gitleaks.toml for custom rules (AWS keys, API keys, private key headers) and allowlists for test fixtures.

API Security Testing

Authentication Bypass

• JWT manipulation: Change alg to none, RS256-to-HS256 confusion, claim modification (role: "admin", exp: 9999999999)
• Session fixation: Check if session ID changes after authentication

Authorization Flaws

• IDOR/BOLA: Change resource IDs in every endpoint — test read, update, delete across users
• BFLA: Regular user tries admin endpoints (expect 403)
• Mass assignment: Add privileged fields (role, is_admin) to update requests

Rate Limiting & GraphQL

• Rate limiting: Rapid-fire requests to auth endpoints; expect 429 after threshold
• GraphQL: Test introspection (should be disabled in prod), query depth attacks, batch mutations bypassing rate limits

See attack_patterns.md for complete JWT manipulation payloads, IDOR testing methodology, BFLA endpoint lists, GraphQL introspection/depth/batch attack patterns, and rate limiting bypass techniques.

Web Vulnerability Testing

See attack_patterns.md for complete test payloads (XSS filter bypasses, context-specific XSS, SQL injection per database engine, SSRF bypass techniques, and DOM-based XSS source/sink pairs).

Infrastructure Security

Key checks:

• Cloud storage: S3 bucket public access (aws s3 ls s3://bucket --no-sign-request), bucket policies, ACLs
• HTTP security headers: HSTS, CSP (no unsafe-inline/unsafe-eval), X-Content-Type-Options, X-Frame-Options, Referrer-Policy
• TLS configuration: nmap --script ssl-enum-ciphers -p 443 target.com or testssl.sh — reject TLS 1.0/1.1, RC4, 3DES, export-grade ciphers
• Port scanning: nmap -sV target.com — flag dangerous open ports (FTP/21, Telnet/23, Redis/6379, MongoDB/27017)

Pen Test Report Generation

Generate professional reports from structured findings:

# Generate markdown report from findings JSON
python scripts/pentest_report_generator.py --findings findings.json --form