From 515718456335955e76af0b5f75edf16f15b296fb Mon Sep 17 00:00:00 2001
From: Leon Luttenberger <LeonLuttenberger@users.noreply.github.com>
Date: Tue, 5 Dec 2023 05:13:35 -0600
Subject: [PATCH] fix: Add parameterized queries where possible to address the
 risk of SQL injection (#2540)

* fix 3 instances of potential SQL injection

* formatting fix

* fix data API rds formatting
---
 awswrangler/data_api/rds.py | 10 +++++++++-
 awswrangler/mysql.py        | 23 ++++++++++++++++-------
 awswrangler/sqlserver.py    | 16 ++++++++++++----
 3 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/awswrangler/data_api/rds.py b/awswrangler/data_api/rds.py
index e9a5e9d86..698db2621 100644
--- a/awswrangler/data_api/rds.py
+++ b/awswrangler/data_api/rds.py
@@ -292,7 +292,15 @@ def _drop_table(con: RdsDataApi, table: str, database: str, transaction_id: str,
 
 
 def _does_table_exist(con: RdsDataApi, table: str, database: str, transaction_id: str) -> bool:
-    res = con.execute(f"SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = '{table}'")
+    res = con.execute(
+        "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = :table",
+        parameters=[
+            {
+                "name": "table",
+                "value": {"stringValue": table},
+            },
+        ],
+    )
     return not res.empty
 
 
diff --git a/awswrangler/mysql.py b/awswrangler/mysql.py
index 689116897..57eb59f69 100644
--- a/awswrangler/mysql.py
+++ b/awswrangler/mysql.py
@@ -3,7 +3,7 @@
 
 import logging
 import uuid
-from typing import Any, Dict, Iterator, List, Literal, Optional, Tuple, Type, Union, cast, overload
+from typing import TYPE_CHECKING, Any, Dict, Iterator, List, Literal, Optional, Tuple, Type, Union, cast, overload
 
 import boto3
 import pyarrow as pa
@@ -13,12 +13,21 @@
 from awswrangler import _databases as _db_utils
 from awswrangler._config import apply_configs
 
-pymysql = _utils.import_optional_dependency("pymysql")
+if TYPE_CHECKING:
+    try:
+        import pymysql
+        from pymysql.connections import Connection
+        from pymysql.cursors import Cursor
+    except ImportError:
+        pass
+else:
+    pymysql = _utils.import_optional_dependency("pymysql")
+
 
 _logger: logging.Logger = logging.getLogger(__name__)
 
 
-def _validate_connection(con: "pymysql.connections.Connection[Any]") -> None:
+def _validate_connection(con: "Connection[Any]") -> None:
     if not isinstance(con, pymysql.connections.Connection):
         raise exceptions.InvalidConnection(
             "Invalid 'conn' argument, please pass a "
@@ -27,16 +36,16 @@ def _validate_connection(con: "pymysql.connections.Connection[Any]") -> None:
         )
 
 
-def _drop_table(cursor: "pymysql.cursors.Cursor", schema: Optional[str], table: str) -> None:
+def _drop_table(cursor: "Cursor", schema: Optional[str], table: str) -> None:
     schema_str = f"`{schema}`." if schema else ""
     sql = f"DROP TABLE IF EXISTS {schema_str}`{table}`"
     _logger.debug("Drop table query:\n%s", sql)
     cursor.execute(sql)
 
 
-def _does_table_exist(cursor: "pymysql.cursors.Cursor", schema: Optional[str], table: str) -> bool:
+def _does_table_exist(cursor: "Cursor", schema: Optional[str], table: str) -> bool:
     schema_str = f"TABLE_SCHEMA = '{schema}' AND" if schema else ""
-    cursor.execute(f"SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE " f"{schema_str} TABLE_NAME = '{table}'")
+    cursor.execute(f"SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE {schema_str} TABLE_NAME = %s", args=[table])
     return len(cursor.fetchall()) > 0
 
 
@@ -164,7 +173,7 @@ def connect(
         password=attrs.password,
         port=attrs.port,
         host=attrs.host,
-        ssl=attrs.ssl_context,
+        ssl=attrs.ssl_context,  # type: ignore[arg-type]
         read_timeout=read_timeout,
         write_timeout=write_timeout,
         connect_timeout=connect_timeout,
diff --git a/awswrangler/sqlserver.py b/awswrangler/sqlserver.py
index b51c21d6f..2990ec05e 100644
--- a/awswrangler/sqlserver.py
+++ b/awswrangler/sqlserver.py
@@ -3,6 +3,7 @@
 
 import logging
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     Dict,
@@ -26,7 +27,14 @@
 
 __all__ = ["connect", "read_sql_query", "read_sql_table", "to_sql"]
 
-pyodbc = _utils.import_optional_dependency("pyodbc")
+if TYPE_CHECKING:
+    try:
+        import pyodbc
+        from pyodbc import Cursor
+    except ImportError:
+        pass
+else:
+    pyodbc = _utils.import_optional_dependency("pyodbc")
 
 _logger: logging.Logger = logging.getLogger(__name__)
 FuncT = TypeVar("FuncT", bound=Callable[..., Any])
@@ -47,16 +55,16 @@ def _get_table_identifier(schema: Optional[str], table: str) -> str:
     return table_identifier
 
 
-def _drop_table(cursor: "pyodbc.Cursor", schema: Optional[str], table: str) -> None:
+def _drop_table(cursor: "Cursor", schema: Optional[str], table: str) -> None:
     table_identifier = _get_table_identifier(schema, table)
     sql = f"IF OBJECT_ID(N'{table_identifier}', N'U') IS NOT NULL DROP TABLE {table_identifier}"
     _logger.debug("Drop table query:\n%s", sql)
     cursor.execute(sql)
 
 
-def _does_table_exist(cursor: "pyodbc.Cursor", schema: Optional[str], table: str) -> bool:
+def _does_table_exist(cursor: "Cursor", schema: Optional[str], table: str) -> bool:
     schema_str = f"TABLE_SCHEMA = '{schema}' AND" if schema else ""
-    cursor.execute(f"SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE " f"{schema_str} TABLE_NAME = '{table}'")
+    cursor.execute(f"SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE {schema_str} TABLE_NAME = ?", table)
     return len(cursor.fetchall()) > 0