Security Audit Report

Date: 2024-12-27 Last Updated: 2025-01-01 Scope: Full security audit - OWASP Top 10, auth patterns, input validation, secrets handling Auditor: Claude Code

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Executive Summary

The codebase has a strong security posture with proper authentication, parameterized queries, input validation, and field-level encryption for PII. All critical and high-priority vulnerabilities have been remediated.

Overall Security Rating: 9/10

Critical Issues: 0 (all fixed or documented as acceptable) High Issues: 1 (secrets management - not an active vulnerability) Medium Issues: 5 (fix in V1.1) Low Issues: 3 (address when convenient)

Remediation Summary (2025-01-01)

Issue	Description	Status
SEC-001	XSS via template injection	✅ Fixed - HTML escaping added
SEC-002	dangerouslySetInnerHTML	✅ Fixed - DOMPurify sanitization
SEC-003	Missing security headers	✅ Fixed - Headers middleware added
SEC-004	Dev API accepts any credentials	✅ Documented - Dev-only, acceptable
SEC-005	ORDER BY SQL injection	✅ Fixed - Whitelist validation
SEC-006	CORS overly permissive	✅ Fixed - Restricted configuration
SEC-007	Missing role enforcement	✅ Fixed - RBAC filtering added
COMP-006	Field-level encryption	✅ Implemented - AES-256-GCM for PII

Additional Security Improvements: - COMP-003: Authentication events now logged to audit trail - COMP-004: Data access logging implemented - COMP-005: Account lockout after failed login attempts - DATABASE_SCHEMA.sql updated with encryption columns (2025-01-01)

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Critical Issues

SEC-001: XSS via Template Injection ✅ FIXED

Severity: CRITICAL → RESOLVED File: src/services/template_service.py:276-301 OWASP Category: A03:2021 - Injection Fixed: 2025-12-31

Original Problem: Client data (name, email, address) inserted directly into HTML templates without escaping.

Resolution: Added html.escape() to all template placeholder values before substitution.

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SEC-002: dangerouslySetInnerHTML Without Sanitization ✅ FIXED

Severity: CRITICAL → RESOLVED File: frontend/packages/ui/src/components/tour/TourOverlay.tsx:187-217 OWASP Category: A03:2021 - Injection Fixed: 2025-12-31

Original Problem: Three instances of dangerouslySetInnerHTML rendering content without sanitization.

Resolution: Added DOMPurify sanitization to all dangerouslySetInnerHTML usages.

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SEC-003: Missing Security Headers ✅ FIXED

Severity: CRITICAL → RESOLVED File: src/api/main.py OWASP Category: A05:2021 - Security Misconfiguration Fixed: 2025-12-31

Original Problem: No security headers configured (X-Frame-Options, X-Content-Type-Options, CSP, HSTS).

Resolution: Added SecurityHeadersMiddleware with all required headers.

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SEC-004: Development API Accepts Any Credentials ✅ DOCUMENTED

Severity: CRITICAL (dev-only) → ACCEPTABLE File: scripts/local_api.py:233-273 OWASP Category: A07:2021 - Identification and Authentication Failures

Status: Documented as dev-only in ARCHITECTURE.md per AUDIT-001. File is excluded from production deployment.

Mitigation: local_api.py is never deployed to production; production uses src/api/ with proper authentication.

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High Issues

SEC-005: ORDER BY SQL Injection Risk ✅ FIXED

Severity: HIGH → RESOLVED File: src/repositories/base_repository.py:131 OWASP Category: A03:2021 - Injection Fixed: 2025-12-31

Original Problem: order_by parameter accepted raw SQL strings without validation.

Resolution: Implemented whitelist validation for ORDER BY values. Only allowed column names are accepted.

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SEC-006: CORS Overly Permissive ✅ FIXED

Severity: HIGH → RESOLVED File: src/api/main.py:91-98 OWASP Category: A05:2021 - Security Misconfiguration Fixed: 2025-12-31

Original Problem: CORS allowed all methods, headers, and credentials from any origin.

Resolution: Restricted CORS to specific allowed origins, methods (GET, POST, PUT, DELETE, OPTIONS), and headers.

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SEC-007: Missing Role Enforcement on List Endpoints ✅ FIXED

Severity: HIGH → RESOLVED File: src/api/routes/clients.py:66-101 OWASP Category: A01:2021 - Broken Access Control Fixed: 2025-12-31

Original Problem: list_clients() required authentication but not role-based filtering.

Resolution: Implemented RBAC filtering - staff sees all clients, preparers see assigned only, clients see own data only.

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SEC-008: Stripe Test Keys in Plain Text

Severity: HIGH File: .env:44-45 OWASP Category: A02:2021 - Cryptographic Failures

Problem: Real Stripe test keys stored in .env file:

STRIPE_SECRET_KEY=sk_test_51Shvj...

Impact: Keys are exposed locally. While test keys, they should be rotated and better protected.

Fix: Rotate keys, consider AWS Secrets Manager even for development.

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Medium Issues

SEC-009: No Token Revocation Mechanism

Severity: MEDIUM File: src/api/middleware/auth.py OWASP Category: A07:2021 - Identification and Authentication Failures

Problem: JWT-only authentication with no logout or token blacklist. Tokens valid until expiry even after "logout".

Impact: Stolen tokens remain valid, no way to force session termination.

Fix: Implement token blacklist (Redis) or switch to HttpOnly cookies with server-side sessions.

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SEC-010: Payment Bypass Flag

Severity: MEDIUM File: src/api/routes/efiling.py:31-35, 198-290 OWASP Category: A04:2021 - Insecure Design

Problem: Staff can bypass payment requirement via bypass_payment_check=true flag.

Mitigating Factors: - Requires staff role - Logged in audit fields

Impact: Financial controls bypassed if staff account compromised.

Fix: Document compliance justification, consider additional approval workflow.

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SEC-011: Search Parameter Unbounded

Severity: MEDIUM File: src/api/routes/clients.py:70 OWASP Category: A03:2021 - Injection

Problem:

search: Optional[str] = Query(None, description="Search...")

No max_length constraint. Could enable ReDoS or resource exhaustion.

Fix: Add max_length=100 parameter.

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SEC-012: Filename Not Sanitized in S3 Path

Severity: MEDIUM File: scripts/local_api.py:879 OWASP Category: A03:2021 - Injection

Problem:

s3_key = f"{client_id}/{return_id}/{file.filename}"

Filename used directly without sanitization.

Impact: Path traversal unlikely in S3, but could cause display issues or unexpected behavior.

Fix: Use os.path.basename() or sanitize filename.

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SEC-013: Request Size Limits Not Enforced

Severity: MEDIUM File: src/api/main.py, uat-package/nginx.conf OWASP Category: A05:2021 - Security Misconfiguration

Problem: No explicit request size limits configured. Relies on framework defaults.

Impact: Denial of service via large request bodies.

Fix: Add middleware limit and nginx client_max_body_size.

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Low Issues

SEC-014: In-Memory Rate Limiting

Severity: LOW File: src/api/middleware/rate_limiting.py:68 OWASP Category: A05:2021 - Security Misconfiguration

Problem: Rate limiter uses in-memory storage. State lost on restart, doesn't work across multiple instances.

Impact: Rate limiting ineffective in production multi-instance deployment.

Fix: Use Redis-backed rate limiter for production.

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SEC-015: Error Messages May Leak Information

Severity: LOW File: scripts/local_api.py:1513 OWASP Category: A04:2021 - Insecure Design

Problem:

ai_response = f"I apologize, but I encountered an error: {str(e)}"

Exception details exposed to users.

Status: Acceptable for local development only.

Fix: Log full error, return generic message in production.

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SEC-016: Email Query Parameter Not Validated

Severity: LOW File: src/api/routes/registration.py:252 OWASP Category: A03:2021 - Injection

Problem:

email: str = Query(..., description="Email address to check")

Should use EmailStr validator like other endpoints.

Fix: Change to email: EmailStr = Query(...).

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Positive Findings

Area	Assessment
JWT Authentication	Well implemented with role hierarchy
Parameterized Queries	Used correctly throughout repositories
Pydantic Validation	All API inputs validated with models
Password Handling	No plaintext passwords in code
.gitignore	Secrets files properly excluded
AWS Credentials	Uses IAM roles, not hardcoded
Rate Limiting	Implemented (needs Redis for prod)
Error Handler	Hides stack traces from clients
RBAC	Permission matrix well defined, enforced on endpoints
Audit Logging	Comprehensive - auth events, data access, modifications
Field-Level Encryption	AES-256-GCM for PII (SSN, DOB, AGI, PTIN)
Security Headers	X-Frame-Options, CSP, HSTS, X-Content-Type-Options
XSS Protection	HTML escaping and DOMPurify sanitization
Account Lockout	Implemented after failed login attempts
Input Validation	ORDER BY whitelist, CORS restrictions

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Recommendations by Priority

Before Production (P0) ✅ COMPLETE

All P0 items have been resolved: 1. ~~SEC-001: Add HTML escaping to template service~~ ✅ Fixed 2. ~~SEC-002: Add DOMPurify or remove dangerouslySetInnerHTML~~ ✅ Fixed 3. ~~SEC-003: Add security headers middleware~~ ✅ Fixed 4. ~~SEC-005: Whitelist ORDER BY values~~ ✅ Fixed 5. ~~SEC-006: Restrict CORS configuration~~ ✅ Fixed 6. ~~SEC-007: Add role-based filtering to list endpoints~~ ✅ Fixed

V1.1 (P1)

1. SEC-008: Rotate Stripe keys, improve secrets management
2. SEC-009: Implement token revocation
3. SEC-010: Document payment bypass compliance
4. SEC-011: Add max_length to search parameter
5. SEC-012: Sanitize filenames
6. SEC-013: Add request size limits

Future (P2)

1. SEC-014: Redis-backed rate limiting
2. SEC-015: Generic error messages in production
3. SEC-016: EmailStr validation on query param

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References

• OWASP Top 10 2021: https://owasp.org/Top10/
• OWASP ASVS: https://owasp.org/www-project-application-security-verification-standard/
• Related: docs/SECURITY_DESIGN.md

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Audit performed by Claude Code