n8n Security Testing

<default_to_action> When testing n8n security:

1. SCAN for credential exposure in workflows
2. VERIFY encryption of sensitive data
3. TEST OAuth token handling
4. CHECK for insecure data transmission
5. VALIDATE input sanitization

Quick Security Checklist:

• No credentials in workflow JSON
• No credentials in execution logs
• OAuth tokens properly encrypted
• API keys not in version control
• Webhook authentication enabled
• Input data sanitized

Critical Success Factors:

• Scan all workflow exports
• Test credential rotation
• Verify encryption at rest
• Check audit logging </default_to_action>

Quick Reference Card

Security Risk Areas

Area	Risk Level	Testing Focus
Credential Storage	Critical	Encryption, exposure
Webhook Security	High	Authentication, validation
Expression Injection	High	Input sanitization
Data Leakage	Medium	Logging, error messages
OAuth Flows	Medium	Token handling, refresh

Credential Types

Type	Exposure Risk	Rotation
API Keys	High if exposed	Manual
OAuth Tokens	Medium (short-lived)	Automatic
Passwords	Critical	Manual
Webhooks	Medium	Generate new

---

Credential Security Testing

Scan for Exposed Credentials

// Scan workflow JSON for credential exposure
async function scanForExposedCredentials(workflowId: string): Promise<CredentialScanResult> {
  const workflow = await getWorkflow(workflowId);
  const workflowJson = JSON.stringify(workflow, null, 2);

  const sensitivePatterns = [
    // API Keys
    { name: 'Generic API Key', pattern: /api[_-]?key["\s:=]+["']?([a-zA-Z0-9_-]{20,})["']?/gi },
    { name: 'AWS Access Key', pattern: /AKIA[0-9A-Z]{16}/g },
    { name: 'AWS Secret Key', pattern: /[a-zA-Z0-9/+=]{40}/g },
    // Tokens
    { name: 'Bearer Token', pattern: /bearer\s+[a-zA-Z0-9_-]{20,}/gi },
    { name: 'JWT Token', pattern: /eyJ[a-zA-Z0-9_-]*\.eyJ[a-zA-Z0-9_-]*\.[a-zA-Z0-9_-]*/g },
    { name: 'Slack Token', pattern: /xox[baprs]-[0-9]{10,13}-[0-9]{10,13}-[a-zA-Z0-9]{24}/g },
    // Passwords
    { name: 'Password Field', pattern: /"password":\s*"[^"]+"/gi },
    { name: 'Secret Field', pattern: /"secret":\s*"[^"]+"/gi },
    // OAuth
    { name: 'Client Secret', pattern: /client[_-]?secret["\s:=]+["']?([a-zA-Z0-9_-]{20,})["']?/gi },
    { name: 'Refresh Token', pattern: /refresh[_-]?token["\s:=]+["']?([a-zA-Z0-9_-]{20,})["']?/gi }
  ];

  const findings: CredentialFinding[] = [];

  for (const pattern of sensitivePatterns) {
    const matches = workflowJson.match(pattern.pattern);
    if (matches) {
      for (const match of matches) {
        findings.push({
          type: pattern.name,
          location: findLocationInWorkflow(workflow, match),
          severity: 'CRITICAL',
          recommendation: `Remove ${pattern.name} from workflow. Use n8n credentials instead.`
        });
      }
    }
  }

  return {
    workflowId,
    scanned: true,
    findingsCount: findings.length,
    findings,
    secure: findings.length === 0
  };
}

Verify Credential Encryption

// Verify credentials are encrypted at rest
async function verifyCredentialEncryption(credentialId: string): Promise<EncryptionResult> {
  // Get credential metadata (not the actual credential)
  const credential = await getCredentialMetadata(credentialId);

  // Check if credential data is encrypted
  const encryptionChecks = {
    // Check if stored data looks encrypted (not plain text)
    isEncrypted: !isPlainText(credential.data),
    // Check encryption algorithm
    algorithm: credential.encryptionAlgorithm || 'unknown',
    // Check key derivation
    keyDerivation: credential.keyDerivation || 'unknown',
    // Check if using instance encryption key
    instanceEncryption: credential.useInstanceKey || false
  };

  return {
    credentialId,
    credentialName: credential.name,
    credentialType: credential.type,
    encryption: encryptionChecks,
    secure: encryptionChecks.isEncrypted && encryptionChecks.algorithm !== 'unknown',
    recommendations: generateEncryptionRecommendations(encryptionChecks)
  };
}

// Check if data appears to be plain text
function isPlainText(data: string): boolean {
  // Plain text credentials often have recognizable patterns
  const plainTextPatterns = [
    /^[a-zA-Z0-9_-]+$/, // Simple alphanumeric
    /^sk-[a-zA-Z0-9]+$/, // API key format
    /^Bearer\s/, // Bearer token
  ];

  return plainTextPatterns.some(p => p.test(data));
}

Test Credential Rotation

// Test credential rotation process
async function testCredentialRotation(credentialId: string): Promise<RotationTestResult> {
  const credential = await getCredentialMetadata(credentialId);

  const rotationTests = {
    // Check if credential has rotation metadata
    hasRotationSchedule: !!credential.rotationSchedule,
    lastRotated: credential.lastRotatedAt,
    rotationDue: isRotationDue(credential),

    // Test OAuth token refresh
    oauthRefresh: credential.type.includes('oauth')
      ? await testOAuthRefresh(credentialId)
      : null,

    // Check credential age
    credentialAge: calculateAge(credential.createdAt),
    isStale: calculateAge(credential.createdAt) > 90 // 90 days
  };

  return {
    credentialId,
    rotationTests,
    recommendations: generateRotationRecommendations(rotationTests)
  };
}

// Test OAuth token refresh
async function testOAuthRefresh(credentialId: string): Promise<OAuthRefreshResult> {
  try {
    // Trigger refresh
    const refreshed = await refreshCredential(credentialId);

    return {
      success: true,
      newExpiry: refreshed.expiresAt,
      refreshedAt: new Date()
    };
  } catch (error) {
    return {
      success: false,
      error: error.message,
      recommendation: 'Re-authorize OAuth connection'
    };
  }
}

---

Webhook Security Testing

Authentication Testing

// Test webhook authentication enforcement
async function testWebhookAuthentication(webhookUrl: string): Promise<WebhookAuthResult> {
  const authTests = [
    // No authentication
    {
      name: 'No Auth',
      headers: {},
      expectedStatus: 401
    },
    // Invalid Basic Auth
    {
      name: 'Invalid Basic Auth',
      headers: { 'Authorization': 'Basic aW52YWxpZDppbnZhbGlk' },
      expectedStatus: 401
    },
    // Invalid Bearer Token
    {
      name: 'Invalid Bearer',
      headers: { 'Authorization': 'Bearer invalid-token-12345' },
      expectedStatus: 401
    },
    // Invalid Header Auth
    {
      name: 'Invalid Header Auth',
      headers: { 'X-API-Key': 'invalid-key' },
      expectedStatus: 401
    }
  ];

  const results: AuthTestResult[] = [];

  for (const test of authTests) {
    const response = await fetch(webhookUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        ...test.headers
      },
      body: '{}'
    });

    results.push({
      test: test.name,
      status: response.status,
      passed: response.status === test.expectedStatus,
      actualStatus: response.status,
      expectedStatus: test.expectedStatus
    });
  }

  // Check if webhook has ANY auth
  const noAuthResponse = results.find(r => r.test === 'No Auth');
  const webhookHasAuth = noAuthResponse?.status === 401;

  return {
    webhookUrl,
    hasAuthentication: webhookHasAuth,
    testResults: results,
    allTestsPassed: results.every(r => r.passed),
    recommendation: !webhookHasAuth
      ? 'CRITICAL: Enable authentication on webhook'
      : null
  };
}

Input Validation Testing

// Test webhook input validation
async function testWebhookInputValidation(webhookUrl: string): Promise<InputValidationResult> {
  const maliciousPayloads = [
    // XSS attempts
    {
      name: 'XSS Script Tag',
      payload: { text: '<script>alert("xss")</script>' },
      check: 'sanitized'
    },
    {
      name: 'XSS Event Handler',
      payload: { text: '<img onerror="alert(1)" src="x">' },
      check: 'sanitized'
    },
    // SQL Injection
    {
      name: 'SQL Injection',
      payload: { id: "1; DROP TABLE users; --" },
      check: 'escaped'
    },
    // Command Injection
    {
      name: 'Command Injection',
      payload: { filename: '; rm -rf /' },
      check: 'rejected'
    },
    // Path Traversal
    {
      name: 'Path Traversal',
      payload: { path: '../../../etc/passwd' },
      check: 'rejected'
    },
    // JSON Injection
    {
      name: 'JSON Injection',
      payload: { data: '{"admin": true}' },
      check: 'escaped'
    },
    // Oversized payload
    {
      name: 'Oversized Payload',
      payload: { data: 'x'.repeat(10000000) }, // 10MB
      check: 'rejected'
    }
  ];

  const results: ValidationTestResult[] = [];

  for (const test of maliciousPayloads) {
    try {
      const response = await fetch(webhookUrl, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(test.payload)
      });

      const responseBody = await response.text();

      results.push({
        test: test.name,
        status: response.status,
        handled: response.status !== 500, // Not a server error
        sanitized: !responseBody.includes(test.payload.text || test.payload.data),
        recommendation: response.status === 500
          ? `Input not handled safely: ${test.name}`
          : null
      });
    } catch (error) {
      results.push({
        test: test.name,
        handled: false,
        error: error.message
      });
    }
  }

  return {
    webhookUrl,
    testsRun: maliciousPayloads.length,
    passed: results.filter(r => r.handled).length,
    failed: results.filter(r => !r.handled).length,
    results,
    secure: results.every(r => r.handled)
  };
}

---

Expression Security Testing

Detect Dangerous Expressions

// Scan expressions for security vulnerabilities
async function scanExpressionsForSecurity(workflowId: string): Promise<ExpressionSecurityResult> {
  const workflow = await getWorkflow(workflowId);
  const expressions = extractExpressions(workflow);

  const dangerousPatterns = [
    // Code execution
    { name: 'eval()', pattern: /eval\s*\(/g, severity: 'CRITICAL' },
    { name: 'Function()', pattern: /new\s+Function\s*\(/g, severity: 'CRITICAL' },
    { name: 'setTimeout string', pattern: /setTimeout\s*\(\s*["'`]/g, severity: 'HIGH' },
    { name: 'setInterval string', pattern: /setInterval\s*\(\s*["'`]/g, severity: 'HIGH' },

    // File system access
    { name: 'require()', pattern: /require\s*\(/g, severity: 'HIGH' },
    { name: 'import()', pattern: /import\s*\(/g, severity: 'HIGH' },
    { name: 'fs access', pattern: /\bfs\./g, severity: 'HIGH' },

    // Process/child execution
    { name: 'child_process', pattern: /child_process/g, severity: 'CRITICAL' },
    { name: 'process.', pattern: /process\./g, severity: 'MEDIUM' },
    { name: 'exec()', pattern: /exec\s*\(/g, severity: 'CRITICAL' },
    { name: 'spawn()', pattern: /spawn\s*\(/g, severity: 'CRITICAL' },

    // Network access
    { name: 'fetch()', pattern: /fetch\s*\(/g, severity: 'MEDIUM' },
    { name: 'XMLHttpRequest', pattern: /XMLHttpRequest/g, severity: 'MEDIUM' },

    // Prototype pollution
    { name: '__proto__', pattern: /__proto__/g, severity: 'HIGH' },
    { name: 'constructor.prototype', pattern: /constructor\.prototype/g, severity: 'HIGH' }
  ];

  const findings: SecurityFinding[] = [];

  for (const expr of expressions) {
    for (const pattern of dangerousPatterns) {
      if (pattern.pattern.test(expr.expression)) {
        findings.push({
          node: expr.nodeName,
          parameter: expr.parameter,
          expression: expr.expression,
          pattern: pattern.name,
          severity: pattern.severity,
          recommendation: `Remove ${pattern.name} from expression. Use safer alternatives.`
        });
      }
    }
  }

  return {
    workflowId,
    expressionsScanned: expressions.length,
    findings,
    secure: findings.length === 0,
    criticalIssues: findings.filter(f => f.severity === 'CRITICAL').length,
    highIssues: findings.filter(f => f.severity === 'HIGH').length
  };
}

---

Data Leakage Testing

Scan Execution Logs

// Scan execution logs for credential leakage
async function scanExecutionLogs(workflowId: string, executionCount: number = 10): Promise<LogScanResult> {
  const executions = await getRecentExecutions(workflowId, executionCount);
  const findings: LogFinding[] = [];

  const sensitivePatterns = [
    { name: 'Password', pattern: /password["\s:=]+["']?[^"'\s]+["']?/gi },
    { name: 'API Key', pattern: /api[_-]?key["\s:=]+["']?[^"'\s]{20,}["']?/gi },
    { name: 'Token', pattern: /token["\s:=]+["']?[a-zA-Z0-9_-]{20,}["']?/gi },
    { name: 'Secret', pattern: /secret["\s:=]+["']?[^"'\s]+["']?/gi },
    { name: 'Authorization Header', pattern: /authorization["\s:]+["']?(bearer|basic)\s+[^"'\s]+["']?/gi }
  ];

  for (const execution of executions) {
    const logString = JSON.stringify(execution.data, null, 2);

    for (const pattern of sensitivePatterns) {
      const matches = logString.match(pattern.pattern);
      if (matches) {
        findings.push({
          executionId: execution.id,
          type: pattern.name,
          matchCount: matches.length,
          severity: 'HIGH',
          recommendation: `Mask ${pattern.name} in logs`
        });
      }
    }
  }

  return {
    workflowId,
    executionsScanned: executions.length,
    findings,
    secure: findings.length === 0,
    recommendation: findings.length > 0
      ? 'Enable credential masking in n8n settings'
      : null
  };
}

Check Error Message Exposure

// Check if error messages expose sensitive information
async function checkErrorMessageSecurity(workflowId: string): Promise<ErrorMessageResult> {
  // Trigger intentional errors
  const errorScenarios = [
    { name: 'Invalid credentials', inject: { credentials: null } },
    { name: 'Invalid endpoint', inject: { url: 'https://invalid' } },
    { name: 'Database error', inject: { query: 'INVALID SQL' } }
  ];

  const findings: ErrorFinding[] = [];

  for (const scenario of errorScenarios) {
    try {
      await executeWithError(workflowId, scenario.inject);
    } catch (error) {
      const errorMessage = error.message;

      // Check for sensitive data in error
      const sensitiveData = [
        { name: 'Connection string', pattern: /mongodb:\/\/[^@]+@/i },
        { name: 'Password in URL', pattern: /:\/\/[^:]+:[^@]+@/i },
        { name: 'Full file path', pattern: /\/(?:home|Users|var)\/[^\s]+/i },
        { name: 'Stack trace', pattern: /at\s+\w+\s+\([^)]+\)/i },
        { name: 'Internal IP', pattern: /\b(?:10|172\.(?:1[6-9]|2[0-9]|3[01])|192\.168)\.\d+\.\d+\b/i }
      ];

      for (const check of sensitiveData) {
        if (check.pattern.test(errorMessage)) {
          findings.push({
            scenario: scenario.name,
            exposedData: check.name,
            severity: 'MEDIUM',
            recommendation: `Sanitize ${check.name} from error messages`
          });
        }
      }
    }
  }

  return {
    workflowId,
    scenariosTested: errorScenarios.length,
    findings,
    secure: findings.length === 0
  };
}

---

Security Report Template

# n8n Security Audit Report

## Summary
| Category | Status | Findings |
|----------|--------|----------|
| Credential Security | PASS/FAIL | X issues |
| Webhook Security | PASS/FAIL | X issues |
| Expression Security | PASS/FAIL | X issues |
| Data Leakage | PASS/FAIL | X issues |

## Critical Findings

### CRIT-001: API Key Exposed in Workflow
- **Location:** HTTP Request node, URL parameter
- **Impact:** Credential theft, unauthorized access
- **Fix:** Move to n8n credentials store

### CRIT-002: eval() in Expression
- **Location:** Set node, custom field
- **Impact:** Remote code execution
- **Fix:** Remove eval, use explicit logic

## Recommendations

1. **Enable webhook authentication** - All public webhooks
2. **Rotate exposed credentials** - Immediately
3. **Enable log masking** - For all credentials
4. **Regular security scans** - Weekly automated scans

## Compliance Status
- OWASP Top 10: X/10 addressed
- SOC 2: Partially compliant
- GDPR: Review data handling

---

Related Skills

• n8n-workflow-testing-fundamentals
• n8n-integration-testing-patterns
• compliance-testing

---

Remember

n8n handles sensitive credentials for 400+ integrations. Security testing requires:

• Credential exposure scanning
• Encryption verification
• Webhook authentication testing
• Expression security analysis
• Data leakage detection

Critical practices: Never expose credentials in workflow JSON. Enable webhook authentication. Mask sensitive data in logs. Rotate credentials regularly. Scan expressions for dangerous functions.