Project: Domain Search MCP Audit Date: December 2024 Audit Type: Comprehensive Security Review

This codebase has undergone multiple layers of security analysis using both AI-powered code review tools and static analysis security scanners. All identified vulnerabilities have been addressed, and the remaining findings have been analyzed and documented as acceptable risks.

Overall Security Posture: PRODUCTION READY

Location: src/registrars/namecheap.ts Issue: External service call to determine client IP exposed user's IP address to third-party service. CWE: CWE-200 (Exposure of Sensitive Information)

Resolution:

• Removed external IP lookup dependency
• IP now configured via NAMECHEAP_CLIENT_IP environment variable
• Added IP format validation (IPv4/IPv6)

// Before (vulnerable)
const ip = await axios.get('https://external-ip-service.com');

// After (secure)
const ip = config.namecheap.clientIp; // User-configured, no external call

Location: src/utils/cache.ts Issue: Cache had no size limit, allowing potential memory exhaustion through repeated unique queries. CWE: CWE-400 (Uncontrolled Resource Consumption)

Resolution:

• Implemented LRU (Least Recently Used) eviction policy
• Added configurable maximum cache size (default: 10,000 entries)
• Added lastAccessedAt tracking for intelligent eviction

// Cache now implements size limits with LRU eviction
const DEFAULT_MAX_CACHE_SIZE = 10000; // ~10MB max memory

Location: src/registrars/porkbun.ts, src/registrars/namecheap.ts, src/fallbacks/rdap.ts Issue: External API responses were used without schema validation, risking type confusion or injection. CWE: CWE-20 (Improper Input Validation)

Resolution:

• Added Zod schema validation for all external API responses
• Implemented strict type inference from schemas
• Added safe parsing with .safeParse() for graceful error handling

// All external responses now validated
const parseResult = ResponseSchema.safeParse(response.data);
if (!parseResult.success) {
  throw new RegistrarApiError('Invalid API response format');
}

Location: src/fallbacks/rdap.ts Issue: RDAP vCard arrays accessed without bounds checking, risking crashes on malformed data. CWE: CWE-129 (Improper Validation of Array Index)

Resolution:

• Added comprehensive bounds checking before array access
• Wrapped extraction in try-catch for defensive error handling
• Validated array structure at each nesting level

// Safe extraction with bounds checking
if (!Array.isArray(vcardArray) || vcardArray.length < 2) {
  return undefined;
}

Location: src/registrars/namecheap.ts:77,94 Scanner Finding: "Potential ReDoS via dynamic RegExp" Severity Reported: Medium

Analysis:

Conclusion: FALSE POSITIVE The scanner cannot determine that the tag parameter is constrained by a compile-time whitelist. The regex pattern itself is mathematically immune to ReDoS attacks.

Mitigation: Whitelist validation occurs before RegExp construction:

const ALLOWED_XML_TAGS = new Set(['Error', 'Errors', 'DomainCheckResult']);

if (!ALLOWED_XML_TAGS.has(tag)) {
  return undefined; // Reject non-whitelisted tags
}

Location: examples/*.ts Scanner Finding: "Unsafe format string concatenation" Severity Reported: Info

Analysis:

• Located in example/demo files only
• Not part of production server code
• No user input reaches these code paths
• Examples run locally by developers only

Conclusion: ACCEPTABLE - Example code, not production

Scan Date: December 2024
Vulnerabilities Found: 0

Dependencies Analyzed:
├── @modelcontextprotocol/sdk (runtime)
├── axios (runtime)
├── zod (runtime)
├── dotenv (runtime)
├── winston (runtime)
└── [dev dependencies excluded from production]

Recommendation: No immediate action required. Schedule major version upgrades during planned maintenance windows.

┌─────────────────────────────────────────────────────────┐
│                    MCP Protocol Layer                    │
│              (Zod schema validation at entry)            │
├─────────────────────────────────────────────────────────┤
│                   Input Validation                       │
│        (Domain/TLD validators with sanitization)         │
├─────────────────────────────────────────────────────────┤
│                   Rate Limiting                          │
│           (Token bucket per registrar adapter)           │
├─────────────────────────────────────────────────────────┤
│                  Response Validation                     │
│         (Zod schemas for all external APIs)              │
├─────────────────────────────────────────────────────────┤
│                   Resource Limits                        │
│        (LRU cache eviction, request timeouts)            │
└─────────────────────────────────────────────────────────┘

1. Before adding new external APIs: Add Zod schema validation for responses
2. Before adding user-facing inputs: Validate and sanitize at entry point
3. When modifying cache logic: Maintain size limits and eviction policies
4. When updating dependencies: Run vulnerability scan before merging
5. For sensitive configurations: Use environment variables, never commit secrets

This security review employed a multi-layer approach:

1. AI-Powered Code Review - Semantic analysis for logic flaws, security anti-patterns, and architectural issues
2. Static Application Security Testing (SAST) - Pattern-based scanning for OWASP Top 10, CWE vulnerabilities
3. Software Composition Analysis (SCA) - Dependency vulnerability database matching
4. Manual Code Review - Verification of automated findings, false positive elimination

Each finding was triaged using:

• Exploitability assessment - Can this actually be exploited?
• Data flow analysis - Where does the data come from?
• Framework context - What protections exist at other layers?

This codebase has been reviewed and approved for production deployment.

Security Review: PASSED
Last Updated: December 2024
Next Review: Recommended before major version releases