# Security Policy
## Supported Versions
| Version | Supported |
| ------- | ------------------ |
| 0.2.x | :white_check_mark: |
| 0.1.x | :white_check_mark: |
## Security Model
This MCP server is designed with security as a primary concern for database access:
### Read-Only by Design
- **SELECT only**: Only queries starting with `SELECT` are allowed
- **Keyword blocking**: Dangerous SQL keywords are blocked even in subqueries:
- `INSERT`, `UPDATE`, `DELETE`, `DROP`, `CREATE`, `ALTER`
- `EXEC`, `EXECUTE`, `TRUNCATE`, `GRANT`, `REVOKE`, `DENY`
- `BACKUP`, `RESTORE`, `SHUTDOWN`, `DBCC`
### Authentication
- **Windows Authentication only**: Uses `Trusted_Connection=yes`
- **No credential storage**: No passwords stored in configuration
- **Domain security**: Leverages existing Windows/Active Directory security
### Resource Protection
- **Row limiting**: Maximum 1000 rows per query (configurable, default 100)
- **No network exposure**: stdio transport only (no HTTP endpoints)
- **Query validation**: All queries validated before execution
## Reporting a Vulnerability
If you discover a security vulnerability, please report it responsibly:
1. **Do NOT** open a public GitHub issue for security vulnerabilities
2. **Email**: Send details to the repository owner privately
3. **Include**:
- Description of the vulnerability
- Steps to reproduce
- Potential impact
- Suggested fix (if any)
### Response Timeline
- **Acknowledgment**: Within 48 hours
- **Initial assessment**: Within 1 week
- **Resolution target**: Within 30 days for critical issues
## Security Best Practices for Users
When deploying this MCP server:
1. **Least privilege**: Grant only SELECT permissions to the Windows account
2. **Network isolation**: Run on machines with direct SQL Server access
3. **Audit logging**: Enable SQL Server audit logging for the service account
4. **Regular updates**: Keep dependencies updated (especially pyodbc)
## Known Limitations
- Keyword blocking is pattern-based and may not catch all edge cases
- Windows Authentication requires the server to run under a domain account
- No query complexity analysis (expensive queries are not blocked)
## Security Updates
Security updates will be released as patch versions (e.g., 0.1.1, 0.1.2).
Subscribe to repository releases to be notified of security updates.
