Security Auditor Agent Skill

Security Auditor

Comprehensive security scanning for codebases. Identifies vulnerabilities before they become incidents. Focuses on actionable findings with remediation guidance.

When to Use

Use for:

• Pre-deployment security audits
• Dependency vulnerability scanning
• Secret/credential leak detection
• Code-level SAST (Static Application Security Testing)
• Security posture reports for stakeholders
• OWASP Top 10 compliance checking
• Pre-PR security reviews

Do NOT use for:

• Runtime security (WAF, rate limiting) - use infrastructure tools
• Network security/firewall rules - use cloud/DevOps skills
• SOC2/HIPAA/PCI compliance - requires legal/organizational process
• Penetration testing execution - this is detection, not exploitation

Quick Start

Full Security Audit

# Run comprehensive scan
./scripts/full-audit.sh /path/to/project

# Output: security-report.json + summary

Quick Checks

# Dependency vulnerabilities only
npm audit --json > deps-audit.json

# Secret detection only
./scripts/detect-secrets.sh /path/to/project

# OWASP check specific file
./scripts/owasp-check.py /path/to/file.js

Core Scanning Capabilities

1. Dependency Scanning

| Package Manager | Command | Severity Levels |

|-----------------|---------|-----------------|

| npm | npm audit --json | critical, high, moderate, low |

| yarn | yarn audit --json | same as npm |

| pip | pip-audit --format json | critical, high, medium, low |

| cargo | cargo audit --json | same |

Decision Tree:

Critical severity found?
├── YES → Block deployment, immediate fix required
│   └── Check if patch available → npm audit fix --force
├── NO → High severity?
    ├── YES → Fix within sprint, document if deferred
    └── NO → Low/Moderate → Track, fix during maintenance

2. Secret Detection

High-Risk Patterns:

• API keys: /[A-Za-z0-9_]{20,}/ near "key", "api", "secret"
• AWS credentials: AKIA[0-9A-Z]{16}
• Private keys: -----BEGIN (RSA|EC|OPENSSH) PRIVATE KEY-----
• JWT tokens: eyJ[A-Za-z0-9_-]+\.eyJ[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+
• Connection strings: ://[^:]+:[^@]+@

Entropy Analysis:

• Shannon entropy > 4.5 on strings > 20 chars = suspicious
• Base64-encoded blobs in source = investigate

False Positive Handling:

Secret-like pattern found?
├── In test file? → Lower severity, document
├── In example/docs? → Check if placeholder
├── High entropy + near "password"/"secret" → High confidence
└── In .env.example? → Acceptable if placeholder values

3. OWASP Top 10 Static Analysis

| # | Vulnerability | Detection Pattern |

|---|---------------|-------------------|

| A01 | Broken Access Control | Missing auth checks on routes |

| A02 | Cryptographic Failures | Weak algorithms (MD5, SHA1 for passwords) |

| A03 | Injection | Unparameterized queries, eval(), innerHTML |

| A04 | Insecure Design | Hardcoded credentials, missing rate limits |

| A05 | Security Misconfiguration | Debug mode in prod, default credentials |

| A06 | Vulnerable Components | Known CVEs in dependencies |

| A07 | Auth Failures | Weak password policies, session issues |

| A08 | Integrity Failures | Unsigned updates, untrusted deserialization |

| A09 | Logging Failures | Sensitive data in logs, missing audit trails |

| A10 | SSRF | Unvalidated URL inputs to fetch/request |

4. Language-Specific Checks

JavaScript/TypeScript:

• eval(), new Function() - code injection
• innerHTML, outerHTML - XSS vectors
• document.write() - DOM-based XSS
• child_process.exec() with user input - command injection
• Regex without timeout - ReDoS vulnerability

Python:

• pickle.loads() with untrusted data - arbitrary code execution
• yaml.load() without Loader=SafeLoader - code injection
• subprocess.shell=True - command injection
• eval(), exec() - code injection
• SQL string concatenation - SQL injection

SQL:

• String concatenation in queries - SQL injection
• LIKE '%' + input + '%' - injection via wildcards
• Missing parameterization - critical vulnerability

Anti-Patterns

Anti-Pattern: Security by Obscurity

What it looks like: "Nobody will find this hardcoded password"

Why wrong: Secrets in source always leak eventually

Instead: Environment variables, secret managers, zero hardcoded secrets

Anti-Pattern: Audit Fatigue

What it looks like: 500 findings, all "medium", team ignores

Why wrong: Critical issues buried in noise

Instead: Prioritize by exploitability, start with critical/high only

Anti-Pattern: Fix Without Understanding

What it looks like: npm audit fix --force without review

Why wrong: May introduce breaking changes, doesn't address root cause

Instead: Review each fix, understand the vulnerability, test after

Anti-Pattern: One-Time Audit

What it looks like: "We did a security audit last year"

Why wrong: New CVEs daily, code changes constantly

Instead: CI/CD integration, weekly automated scans minimum

Security Report Format

{
  "summary": {
    "critical": 0,
    "high": 2,
    "medium": 5,
    "low": 12,
    "informational": 8
  },
  "findings": [
    {
      "id": "SEC-001",
      "severity": "high",
      "category": "A03:Injection",
      "title": "SQL Injection in user search",
      "location": "src/api/users.js:45",
      "description": "User input concatenated directly into SQL query",
      "evidence": "const query = `SELECT * FROM users WHERE name = '${input}'`",
      "remediation": "Use parameterized queries: db.query('SELECT * FROM users WHERE name = $1', [input])",
      "references": ["https://owasp.org/www-community/attacks/SQL_Injection"]
    }
  ],
  "recommendations": [
    "Implement parameterized queries across all database access",
    "Add input validation layer",
    "Enable SQL query logging for monitoring"
  ]
}

CI/CD Integration

GitHub Actions Example

security-scan:
  runs-on: ubuntu-latest
  steps:
    - uses: actions/checkout@v4
    - name: Run security audit
      run: |
        npm audit --json > audit.json
        ./scripts/detect-secrets.sh . > secrets.json
        ./scripts/generate-report.py
    - name: Fail on critical
      run: |
        if jq '.summary.critical > 0' report.json; then
          echo "Critical vulnerabilities found!"
          exit 1
        fi

Scripts (in scripts/ folder)

| Script | Purpose |

|--------|---------|

| full-audit.sh | Comprehensive security scan |

| detect-secrets.sh | High-entropy string and pattern detection |

| owasp-check.py | OWASP Top 10 static analysis |

| generate-report.py | Combine findings into unified report |

Expert vs Novice Approach

| Novice | Expert |

|--------|--------|

| Runs audit once before release | CI/CD integration, every commit |

| Focuses on tool output only | Understands vulnerability context |

| Fixes everything or nothing | Triages by exploitability |

| Uses one scanner | Layers multiple tools |

| Ignores false positives | Tunes detection rules |

Success Metrics

| Metric | Target |

|--------|--------|

| Critical/High pre-production | 0 |

| Mean time to remediate critical | < 24 hours |

| False positive rate | < 10% |

| Scan coverage | 100% of deployable code |

Reference Files

• references/owasp-top-10-2024.md - Detailed OWASP guidance
• references/secret-patterns.md - Comprehensive regex patterns
• references/remediation-playbook.md - Fix guidance by vulnerability type
• references/ci-cd-templates.md - Integration examples
• scripts/ - Working security scanning scripts

Detects: Dependency CVEs | Secret leaks | Injection vulnerabilities | OWASP violations | Security misconfigurations

Use with: site-reliability-engineer (deployment gates) | code-review (PR security checks)