Security Audit Skill

Security audits, vulnerability assessment, and secure coding patterns aligned with OWASP.

Expertise Areas

• Vulnerabilities: XXE, SQL injection, XSS, CSRF, auth flaws, insecure deserialization
• Risk Scoring: CVSS v3.1 methodology
• Secure Coding: Input validation, output encoding, cryptography, session management

Reference Files

• references/xxe-prevention.md - XXE detection and prevention
• references/owasp-top10.md - OWASP Top 10 patterns
• references/cvss-scoring.md - CVSS scoring methodology
• references/api-key-encryption.md - API key encryption at rest (sodium)
• references/secure-php.md - PHP-specific security patterns
• references/secure-config.md - Secure configuration checklists

Quick Patterns

XML parsing (prevent XXE):

$doc->loadXML($input, LIBXML_NONET | LIBXML_NOENT | LIBXML_DTDLOAD);

SQL (prevent injection):

$stmt = $pdo->prepare('SELECT * FROM users WHERE id = ?');
$stmt->execute([$id]);

Output (prevent XSS):

echo htmlspecialchars($input, ENT_QUOTES | ENT_HTML5, 'UTF-8');

API keys (encrypt at rest):

$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$encrypted = 'enc:' . base64_encode($nonce . sodium_crypto_secretbox($apiKey, $nonce, $key));

Security Checklist

• bcrypt/Argon2 for passwords, CSRF tokens on state changes
• All input validated server-side, parameterized SQL
• XML external entities disabled, file uploads restricted
• Context-appropriate output encoding, CSP configured
• API keys encrypted at rest (sodium_crypto_secretbox)
• TLS 1.2+, secrets not in VCS, audit logging

Verification

./scripts/security-audit.sh /path/to/project

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Contributing: https://github.com/netresearch/security-audit-skill