# Security Fixes Implementation Report

**Date:** November 29, 2025  
**Status:** ✅ COMPLETED

---

## Summary

All identified security vulnerabilities from the multi-tenant audit have been implemented and tested. The fixes maintain backward compatibility through configurable flags.

---

## Implemented Fixes

### SEC-001: Remove Global RAG Fallback ✅

**Files Modified:**
- `lightrag/api/config.py` - Added `MULTI_TENANT_STRICT_MODE` flag
- `lightrag/api/dependencies.py` - Updated `get_tenant_context_optional()` to enforce strict mode
- `lightrag/api/routers/document_routes.py` - Updated `get_tenant_rag()` to block fallback in strict mode
- `lightrag/api/routers/query_routes.py` - Updated `get_tenant_rag()` to block fallback in strict mode

**Configuration:**
```bash
# Enable strict multi-tenant mode (default: true)
export LIGHTRAG_MULTI_TENANT_STRICT=true
```

**Behavior:**
- When `LIGHTRAG_MULTI_TENANT_STRICT=true`: Requests without tenant context are rejected with HTTP 400
- When `LIGHTRAG_MULTI_TENANT_STRICT=false`: Falls back to global RAG (backward compatible)

---

### SEC-002: Remove Admin User Bypass ✅

**Files Modified:**
- `lightrag/api/config.py` - Added `SUPER_ADMIN_USERS` configuration
- `lightrag/services/tenant_service.py` - Replaced hardcoded "admin" bypass with configurable super-admin list

**Configuration:**
```bash
# Configure super-admin users (comma-separated list)
export LIGHTRAG_SUPER_ADMIN_USERS="admin@company.com,superuser"
```

**Behavior:**
- Only users explicitly listed in `LIGHTRAG_SUPER_ADMIN_USERS` get super-admin access
- Empty by default (no super-admins)
- Case-insensitive matching

---

### SEC-003: Make user_id Required ✅

**Files Modified:**
- `lightrag/api/config.py` - Added `REQUIRE_USER_AUTH` flag
- `lightrag/tenant_rag_manager.py` - Updated to enforce user_id when flag is enabled

**Configuration:**
```bash
# Require user authentication for tenant access (default: true)
export LIGHTRAG_REQUIRE_USER_AUTH=true
```

**Behavior:**
- When `LIGHTRAG_REQUIRE_USER_AUTH=true`: Requests without user_id are rejected with PermissionError
- When `LIGHTRAG_REQUIRE_USER_AUTH=false`: Allows anonymous access (backward compatible)

---

### WUI-001: Clear localStorage on Logout ✅

**Files Modified:**
- `lightrag_webui/src/stores/state.ts` - Added tenant context clearing in `logout()` function

**Changes:**
```typescript
logout: () => {
  localStorage.removeItem('LIGHTRAG-API-TOKEN');
  // NEW: Clear tenant context on logout
  localStorage.removeItem('SELECTED_TENANT');
  localStorage.removeItem('SELECTED_KB');
  // ...
}
```

---

### WUI-002: Better Error Handling ✅

**Files Modified:**
- `lightrag_webui/src/api/tenant.ts` - Removed fake fallback data on API errors

**Changes:**
- `fetchTenantsPaginated()` now throws errors instead of returning fake default tenant
- `fetchTenants()` now throws errors instead of returning fake default tenant
- UI components can now properly display error states

---

### WUI-003: Validate Tenant Context ✅

**Files Modified:**
- `lightrag_webui/src/api/client.ts` - Added tenant context validation in Axios interceptor

**Changes:**
```typescript
// Endpoints that require tenant context
const TENANT_REQUIRED_ENDPOINTS = [
  '/documents',
  '/query',
  '/graph',
  '/knowledge-bases',
]

// Block requests without tenant context for required endpoints
if (requiresTenantContext(config.url) && (!hasTenantContext || !hasKBContext)) {
  throw new axios.Cancel('Please select a tenant and knowledge base...');
}
```

---

## Configuration Summary

| Variable | Default | Description |
|----------|---------|-------------|
| `LIGHTRAG_MULTI_TENANT_STRICT` | `true` | Enforce tenant context on all data endpoints |
| `LIGHTRAG_REQUIRE_USER_AUTH` | `true` | Require user authentication for tenant access |
| `LIGHTRAG_SUPER_ADMIN_USERS` | `""` | Comma-separated list of super-admin usernames |

---

## Test Results

| Test Suite | Tests | Result |
|------------|-------|--------|
| test_multitenant_e2e.py | 32 | ✅ PASSED |
| test_tenant_security.py | 11 | ✅ PASSED |
| test_multi_tenant_backends.py | 37 | ✅ PASSED |
| test_tenant_storage_phase3.py | 22 | ✅ PASSED |
| **TOTAL** | **102** | **✅ ALL PASSED** |

WebUI Build: ✅ PASSED

---

## Migration Guide

### For Existing Single-Tenant Deployments

If you want to maintain the old behavior (no tenant enforcement):

```bash
export LIGHTRAG_MULTI_TENANT_STRICT=false
export LIGHTRAG_REQUIRE_USER_AUTH=false
```

### For New Multi-Tenant Deployments

The defaults are secure out of the box:

```bash
# These are the defaults, no need to set
export LIGHTRAG_MULTI_TENANT_STRICT=true
export LIGHTRAG_REQUIRE_USER_AUTH=true

# Optionally configure super-admins
export LIGHTRAG_SUPER_ADMIN_USERS="admin@example.com"
```

---

## Security Verification Checklist

| Check | Status |
|-------|--------|
| Global RAG fallback blocked in strict mode | ✅ |
| Admin bypass removed | ✅ |
| User authentication enforced | ✅ |
| Tenant context cleared on logout | ✅ |
| API errors propagated to UI | ✅ |
| Client-side tenant validation | ✅ |
| All tests pass | ✅ |
| WebUI builds successfully | ✅ |

---

## Remaining Recommendations

1. **Enable PostgreSQL RLS** - Add database-level row security as defense-in-depth
2. **Add Audit Logging** - Log cross-tenant access attempts for security monitoring
3. **Rate Limiting** - Implement per-tenant rate limiting to prevent abuse
4. **Use httpOnly Cookies** - Consider moving tokens from localStorage to httpOnly cookies
