security(mysql): replace string concatenation with parameterized queries in schema introspection (#241) (#247)

Author: ZhuchkaTriplesix

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - **SQLite / RETURNING clause support (#243)** — support RETURNING clauses for INSERT, UPDATE, and DELETE DML queries in the SQLite database driver, returning the resulting rows to the client.
+- **Security / MySQL Injection Fix (#241)** — replaced manual escaping and string concatenation in schema introspection methods (`listViews`, `listColumnNames`, `listTables`) in the MySQL database driver with parameterized queries using parameter binding.
 
 ## [0.4.7-a] - 2026-06-22
 

lib/core/database/mysql_connection.dart

@@ -76,9 +76,7 @@ class MysqlConnection {
   bool get _usesConnectionString =>
       connectionString != null && connectionString!.trim().isNotEmpty;
 
-  static String _escapeSqlString(String s) {
-    return s.replaceAll(r'\', r'\\').replaceAll("'", "''");
-  }
+
 
   /// MySQL identifier quoting (backticks).
   static String quoteIdentifier(String id) {
@@ -284,11 +282,11 @@ class MysqlConnection {
     if (!isConnected || _conn == null) {
       throw StateError('Not connected to MySQL');
     }
-    final s = _escapeSqlString(schema);
     final rs = await execute(
       'SELECT TABLE_NAME FROM information_schema.TABLES '
-      "WHERE TABLE_SCHEMA = '$s' AND TABLE_TYPE = 'VIEW' "
+      "WHERE TABLE_SCHEMA = :schema AND TABLE_TYPE = 'VIEW' "
       'ORDER BY TABLE_NAME',
+      {'schema': schema},
     );
     return rs.rows.map((r) => r.colAt(0)!).toList();
   }
@@ -301,12 +299,14 @@ class MysqlConnection {
     if (!isConnected || _conn == null) {
       throw StateError('Not connected to MySQL');
     }
-    final d = _escapeSqlString(database);
-    final t = _escapeSqlString(table);
     final rs = await execute(
       'SELECT COLUMN_NAME FROM information_schema.COLUMNS '
-      "WHERE TABLE_SCHEMA = '$d' AND TABLE_NAME = '$t' "
+      "WHERE TABLE_SCHEMA = :database AND TABLE_NAME = :table "
       'ORDER BY ORDINAL_POSITION',
+      {
+        'database': database,
+        'table': table,
+      },
     );
     return rs.rows.map((r) => r.colAt(0)!).toList();
   }
@@ -316,11 +316,11 @@ class MysqlConnection {
     if (!isConnected || _conn == null) {
       throw StateError('Not connected to MySQL');
     }
-    final s = _escapeSqlString(schema);
     final rs = await execute(
       'SELECT TABLE_NAME FROM information_schema.TABLES '
-      "WHERE TABLE_SCHEMA = '$s' AND TABLE_TYPE = 'BASE TABLE' "
+      "WHERE TABLE_SCHEMA = :schema AND TABLE_TYPE = 'BASE TABLE' "
       'ORDER BY TABLE_NAME',
+      {'schema': schema},
     );
     return rs.rows.map((r) => r.colAt(0)!).toList();
   }

test/core/database/mysql_connection_test.dart

@@ -39,4 +39,93 @@ void main() {
       );
     });
   });
+
+  group('MysqlConnection when not connected', () {
+    late MysqlConnection conn;
+
+    setUp(() {
+      conn = MysqlConnection(
+        id: 1,
+        name: 'test',
+        host: 'localhost',
+      );
+    });
+
+    test('execute throws StateError', () {
+      expect(
+        () => conn.execute('SELECT 1'),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('listDatabases throws StateError', () {
+      expect(
+        () => conn.listDatabases(),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('listViews throws StateError', () {
+      expect(
+        () => conn.listViews(schema: 'db'),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('listColumnNames throws StateError', () {
+      expect(
+        () => conn.listColumnNames(database: 'db', table: 'tbl'),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('listTables throws StateError', () {
+      expect(
+        () => conn.listTables(schema: 'db'),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('serverVersion throws StateError', () {
+      expect(
+        () => conn.serverVersion(),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+
+    test('serverStats throws StateError', () {
+      expect(
+        () => conn.serverStats(),
+        throwsA(isA<StateError>().having(
+          (e) => e.message,
+          'message',
+          contains('Not connected to MySQL'),
+        )),
+      );
+    });
+  });
 }