mcp-server-sql-tool

The server exposes an endpoint to execute arbitrary SQL queries provided by the user, which is inherently high-risk. While a `SqlGuard` is implemented to blacklist dangerous keywords (e.g., INSERT, UPDATE, DELETE, DROP, ALTER, CREATE) and enforce SELECT/WITH statements, such regex-based blacklisting can often be bypassed by sophisticated attackers. The use of `SET LOCAL search_path` based on a sanitized `telegram_id` provides a degree of schema isolation, but its effectiveness relies heavily on the `telegram_id` being correctly sanitized and the database's user/schema permissions being meticulously configured. Direct execution of user-supplied SQL strings via `client.query(q)` (even after validation) is less safe than using parameterized queries with a robust SQL parser. No hardcoded secrets were found; sensitive configurations are managed via environment variables.