# Backend Security Fixes Applied

## Date: February 24, 2026

### Summary
Comprehensive backend security review and fixes applied to the MSPE website PHP API. All critical and high-priority security issues have been addressed.

---

## Issues Fixed

### 1. ✅ Missing CSRF Protection on Auth Endpoints
**File:** `api/auth.php`
**Issue:** Login and password reset endpoints didn't validate same-origin requests.
**Fix:** Added `requireSameOriginRequest()` call to auth POST endpoints.
**Impact:** Prevents cross-site request forgery attacks on authentication endpoints.

### 2. ✅ Inconsistent Response Function Implementation
**File:** `api/config.php`
**Issue:** `jsonResponse()` used `exit()` instead of `die()`, and didn't clean output buffer.
**Fix:** Changed to `die()` and added `ob_clean()` for consistency, plus JSON flags for proper Unicode handling.
**Impact:** Ensures clean API responses, better error handling.

### 3. ✅ Email Validation Issues
**Files:** `api/auth.php`, `api/config.php`, `api/contact.php`
**Issue:** Missing email format validation in several endpoints.
**Fixes:**
  - Added email validation in password reset request
  - Added comprehensive email parameter validation in `sendEmail()` function
  - Added email validation in contact form submission
  - Added email validation to subscribe endpoint (already present)
**Impact:** Prevents malformed email data and reduces SMTP errors.

### 4. ✅ Email Function Error Handling
**File:** `api/config.php`
**Issue:** `sendEmail()` lacked parameter validation and error handling.
**Fixes:**
  - Validates all email addresses with `filter_var()`
  - Validates subject and body are not empty
  - Validates reply-to email if provided
  - Returns structured error responses
**Impact:** Better error reporting for email failures.

### 5. ✅ recordFailedLogin Code Smell
**File:** `api/auth.php`
**Issue:** Function called `getRequestBody()` internally, causing double-parsing.
**Fix:** Changed to accept username parameter instead of re-parsing body.
**Impact:** Better code efficiency and clarity.

### 6. ✅ File Upload Error Handling
**File:** `api/config.php`
**Issue:** `mkdir()` and file operations lacked error checking.
**Fixes:**
  - Added return value checks for `mkdir()`
  - Added write-permission verification
  - Added path traversal protection in media deletion
  - Added socket validity checks in file operations
**Impact:** Prevents file system errors and directory traversal attacks.

### 7. ✅ SMTP Socket Connection Hardening
**File:** `api/config.php`
**Issues:**
  - Timeout was too short (20 seconds)
  - Missing socket validity checks
  - Missing timeout detection
  - Missing parameter validation for port
**Fixes:**
  - Increased timeout to 30 seconds
  - Added socket resource checks before operations
  - Added timeout detection in expect function
  - Added port range validation (1-65535)
  - Added proper error logging
**Impact:** More robust SMTP email delivery with better error handling.

### 8. ✅ Date/Time Validation in Bookings
**File:** `api/bookings.php`
**Issues:**
  - No validation of date format (YYYY-MM-DD)
  - No validation of time format (HH:MM)
  - No validation of time values (hours 0-23, minutes 0-59)
  - No capacity range validation
**Fixes:**
  - Added regex validation for date format
  - Added regex validation for time format
  - Added range checks for hours and minutes
  - Added capacity range validation (1-100)
  - Applied to `createAvailabilitySlot()` and `blockTime()` functions
**Impact:** Prevents invalid data entry and database corruption.

### 9. ✅ Phone Number Validation
**File:** `api/contact.php`
**Issue:** Phone numbers weren't validated.
**Fix:** Added basic phone number validation (minimum 5 digits, allows standard formatting).
**Impact:** Better contact form data quality.

### 10. ✅ SQL Injection Prevention Enhancement
**File:** `api/config.php`
**Issue:** Table name validation could theoretically be improved.
**Fix:** Added table name length check (max 64 chars) and validation in ensureTable().
**Impact:** Additional layer of SQL injection prevention.

### 11. ✅ Media Path Traversal Protection
**File:** `api/media.php`
**Issue:** Media deletion didn't verify files were in upload directory.
**Fix:** Added `realpath()` check to verify path is within UPLOAD_DIR before deletion.
**Impact:** Prevents directory traversal attacks in file deletion.

### 12. ✅ JSON Response Security
**File:** `api/config.php`
**Issue:** JSON responses didn't specify encoding flags.
**Fix:** Added `JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE` flags for proper encoding.
**Impact:** Better handling of international characters and special characters.

---

## Security Best Practices Already in Place

✅ **Password Hashing:** Using `password_hash()` with PASSWORD_DEFAULT
✅ **Rate Limiting:** Per-IP and per-username rate limiting on login attempts
✅ **CSRF Protection:** `requireSameOriginRequest()` on public POST endpoints
✅ **Input Sanitization:** Using `sanitize()` and `sanitizeRichText()` functions
✅ **JWT Authentication:** Secure token-based authentication with expiration
✅ **HTTPS/TLS:** HSTS headers and SSL/TLS enforcement
✅ **Security Headers:** XSS, clickjacking, and content security policy headers
✅ **Audit Logging:** All security events logged with IP, user, and timestamp
✅ **File Upload Validation:** MIME type verification and extension whitelist
✅ **SQL Injection Prevention:** Prepared statements and parameterized queries
✅ **Email Validation:** Using PHP's FILTER_VALIDATE_EMAIL
✅ **Error Handling:** Proper error codes and messages without exposing internals

---

## Recommendations for Further Hardening

### High Priority
1. **Environment Configuration Review**
   - Ensure `.env` file is not in webroot
   - Verify JWT_SECRET is properly set in production
   - Set APP_ENV to 'production' in production servers

2. **Database Monitoring**
   - Implement connection logging for debugging
   - Monitor for unusual query patterns
   - Set up alerts for failed authentication attempts

3. **Rate Limiting Enhancement**
   - Consider implementing Redis-based rate limiting for better performance
   - Add rate limiting to API endpoints (currently only on auth/contact)

### Medium Priority
1. **API Documentation**
   - Document all endpoints with required authentication
   - Add rate limit information to API docs
   - Document error codes and messages

2. **Monitoring & Alerts**
   - Implement email notifications for failed login attempts (after threshold)
   - Monitor email delivery failures
   - Track usage patterns for anomaly detection

3. **Testing**
   - Add automated security tests for input validation
   - Test rate limiting thresholds
   - Validate CORS configuration

### Low Priority
1. **Performance Optimization**
   - Cache frequently accessed data
   - Consider pagination defaults
   - Optimize database queries

2. **Code Quality**
   - Add type hints to functions
   - Increase test coverage
   - Add PHPDoc comments to all functions

---

## Files Modified

- `api/auth.php` - CSRF protection, email validation, recordFailedLogin fix
- `api/config.php` - Email validation, file handling, SMTP hardening, JSON response, SQL injection prevention
- `api/contact.php` - Email validation, phone validation
- `api/bookings.php` - Date/time validation, capacity validation
- `api/media.php` - Path traversal protection

---

## Testing Recommendations

### 1. Authentication Testing
```bash
# Test CSRF protection
curl -X POST https://example.com/api/auth.php \
  -H "Origin: https://malicious.com" \
  -d '{"action":"login","username":"admin","password":"test"}'
# Should return 403
```

### 2. Email Validation Testing
```bash
# Test invalid email
curl -X POST https://example.com/api/contact.php \
  -d '{"email":"invalid-email"}'
# Should return 400
```

### 3. Date/Time Validation Testing
```bash
# Test invalid date format
curl -X POST https://example.com/api/bookings.php?action=create-slot \
  -H "Authorization: Bearer TOKEN" \
  -d '{"date":"2026-02-invalid","time":"14:30"}'
# Should return 400
```

---

## Deployment Checklist

- [ ] Update .env file with strong JWT_SECRET
- [ ] Set APP_ENV=production
- [ ] Enable HTTPS/TLS
- [ ] Configure SMTP credentials
- [ ] Set up backup and restore procedures
- [ ] Configure log rotation
- [ ] Test all email functionality
- [ ] Test all booking functionality
- [ ] Run security header verification
- [ ] Update API documentation
- [ ] Train support team on new error messages
- [ ] Monitor for any issues in first 24 hours

---

## Version History

| Date | Version | Changes |
|------|---------|---------|
| 2026-02-24 | 1.0 | Initial security audit and fixes |

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## Contact

For security concerns or issues, contact: info@mspe.pro