API Security Sentinel

The API Security Sentinel is an advanced API security testing agent that performs intelligent fuzzing, authentication bypass detection, and automated vulnerability discovery for REST, GraphQL, SOAP, and gRPC APIs.

Overview

Category: API & Application Security Speed: Medium (2-5 minutes per endpoint) Scan Cost: 1 credit Supported Protocols: REST, GraphQL, SOAP, gRPC Best For: API penetration testing, OWASP API Top 10, authentication testing

Key Features

🔍 OWASP API Security Top 10 Coverage

Complete coverage of OWASP API Security Top 10 2023 :

Broken Object Level Authorization (BOLA) - Access other users’ data
Broken Authentication - JWT bypass, token manipulation
Broken Object Property Level Authorization - Mass assignment, excessive data exposure
Unrestricted Resource Access - Rate limiting bypass
Broken Function Level Authorization - Privilege escalation
Unrestricted Access to Sensitive Business Flows - Business logic abuse
Server Side Request Forgery (SSRF) - Internal network access
Security Misconfiguration - Verbose errors, CORS issues
Improper Inventory Management - Old API versions, zombie endpoints
Unsafe Consumption of APIs - Third-party API risks

🛡️ Authentication & Authorization Testing

JWT Token Analysis - Weak signatures, algorithm confusion, None algorithm
OAuth 2.0 Testing - Authorization code interception, token theft
Session Management - Fixation, hijacking, predictable tokens
API Key Security - Weak keys, key rotation issues
Role-Based Access Control (RBAC) - Horizontal/vertical privilege escalation

🧪 Intelligent Fuzzing

Parameter Fuzzing - SQL injection, XSS, command injection
HTTP Method Fuzzing - Test all methods (GET, POST, PUT, DELETE, PATCH)
Header Fuzzing - Host header injection, CRLF injection
Content-Type Testing - XML, JSON, form-data, multipart
Rate Limit Testing - Bypass techniques (IP rotation, header manipulation)

📊 GraphQL Security

Introspection Query Analysis - Schema exposure
Query Depth Attacks - Nested query DoS
Batch Query Attacks - Resource exhaustion
Field Duplication - Bypass rate limits
Alias-Based Attacks - Query complexity abuse

💉 Injection Detection

SQL Injection - Boolean-based, time-based, union-based
NoSQL Injection - MongoDB, CouchDB operators
Command Injection - OS command execution
LDAP Injection - Directory traversal
XPath Injection - XML data extraction
Template Injection - Server-side template engines

🔐 Business Logic Vulnerabilities

Price Manipulation - Negative amounts, currency mismatch
Quantity Tampering - Discount abuse, free items
Workflow Bypass - Skip payment, skip verification
Race Conditions - Double spending, parallel requests
Integer Overflow - Large number attacks

Usage

Basic API Scan


# Scan REST API
alprina scan https://api.example.com/v1
 
# Scan with authentication
alprina scan https://api.example.com/v1 \
  --header "Authorization: Bearer YOUR_TOKEN"
 
# GraphQL scan
alprina scan https://api.example.com/graphql --type graphql

Authentication Testing


# Test JWT security
alprina scan https://api.example.com \
  --test-auth \
  --jwt-token "eyJhbGc..."
 
# Test OAuth flows
alprina scan https://api.example.com \
  --test-oauth \
  --client-id "abc123"
 
# Test session management
alprina scan https://api.example.com \
  --test-sessions \
  --cookie "session=xyz"

OWASP API Top 10 Scan


# Full OWASP API Top 10 test
alprina scan https://api.example.com \
  --owasp-api-top10
 
# Focus on specific categories
alprina scan https://api.example.com \
  --test-bola \
  --test-auth \
  --test-rbac

Fuzzing


# Intelligent fuzzing
alprina scan https://api.example.com/users/{id} \
  --fuzz \
  --fuzz-parameters
 
# Custom fuzzing wordlist
alprina scan https://api.example.com \
  --fuzz \
  --wordlist custom-payloads.txt

Output Example


{
  "vulnerabilities": [
    {
      "type": "broken_object_level_authorization",
      "owasp_category": "API1:2023",
      "severity": "high",
      "endpoint": "/api/v1/users/{id}",
      "method": "GET",
      "description": "User can access other users' profiles by changing ID",
      "exploit": "GET /api/v1/users/123 with valid token returns data for user 123",
      "impact": "Unauthorized access to PII, account takeover potential",
      "remediation": "Implement user context validation before returning data"
    },
    {
      "type": "sql_injection",
      "owasp_category": "API8:2023",
      "severity": "critical",
      "endpoint": "/api/v1/search",
      "parameter": "query",
      "payload": "' OR '1'='1",
      "description": "SQL injection in search parameter",
      "impact": "Database compromise, data exfiltration",
      "remediation": "Use parameterized queries, input validation"
    }
  ]
}

Detection Techniques

BOLA (Broken Object Level Authorization)


# Test 1: Try accessing other user IDs
GET /api/users/1 → 200 OK (your user)
GET /api/users/2 → 200 OK (OTHER user) ❌ VULNERABLE
 
# Test 2: UUID enumeration
GET /api/orders/uuid-1 → 200 OK
GET /api/orders/uuid-2 → 200 OK ❌ VULNERABLE

Authentication Bypass


# JWT None Algorithm
Original: {"alg":"RS256",...}
Modified: {"alg":"none",...} ❌ VULNERABLE
 
# JWT Key Confusion
Original: RS256 (asymmetric)
Modified: HS256 (symmetric) with public key ❌ VULNERABLE
 
# Token Not Required
GET /api/users (no Authorization header) → 200 OK ❌ VULNERABLE

Mass Assignment


# Request
POST /api/users
{
  "email": "user@example.com",
  "isAdmin": true  ← Should be ignored
}
 
# Response
{
  "id": 123,
  "email": "user@example.com",
  "isAdmin": true  ← ❌ VULNERABLE
}

Best Practices

Pre-Production API Testing


# Comprehensive API security scan
alprina scan https://staging-api.example.com \
  --owasp-api-top10 \
  --test-auth \
  --fuzz \
  --output api-security-report.pdf
 
# Test all endpoints
alprina scan https://api.example.com \
  --openapi swagger.json \
  --test-all-endpoints

CI/CD Integration


# .github/workflows/api-security.yml
name: API Security Tests
on: [push, pull_request]
 
jobs:
  api-security:
    runs-on: ubuntu-latest
    steps:
      - name: API Security Scan
        run: |
          alprina scan ${{ secrets.STAGING_API_URL }} \
            --owasp-api-top10 \
            --fail-on critical,high \
            --output api-scan-results.json

Rate Limit Testing


# Test rate limiting
alprina scan https://api.example.com \
  --test-rate-limits \
  --requests-per-second 100
 
# Bypass detection
alprina scan https://api.example.com \
  --test-rate-limit-bypass

Performance

Speed: 2-5 minutes per endpoint (basic scan)
Thoroughness: 200+ test cases per endpoint
Accuracy: 90%+ true positive rate
Coverage: OWASP API Top 10 + 150+ additional checks

Pricing

Per Endpoint: 1 credit (~$0.10)
Full API Scan (20 endpoints): ~~20 credits (~~$2.00)
Continuous Monitoring: Pro plan includes unlimited API scans

Compare to traditional API penetration testing:

Manual pen test: $5,000 -$ 15,000 (1-2 weeks)
Alprina API Security Sentinel: $2 -$ 20 (2-30 minutes)

Integration Examples

With Postman Collections


# Import Postman collection
alprina scan --postman-collection api-tests.json

With OpenAPI/Swagger


# Import OpenAPI spec
alprina scan --openapi swagger.yaml --test-all-endpoints

With Burp Suite


# Import Burp Suite requests
alprina scan --burp-xml burp-requests.xml

Common Vulnerabilities Found

Based on real-world scans, the API Security Sentinel most commonly finds:

BOLA - 45% of APIs tested
Broken Authentication - 30% of APIs
Excessive Data Exposure - 25% of APIs
SQL Injection - 15% of APIs
Mass Assignment - 12% of APIs

Next Steps

Read API Security Guide for best practices
Learn about Authentication Testing
Integrate with CI/CD Pipelines
See GraphQL Security specifics