How to fix warning CA2100 for OLEDB connection in C#

Hi,

I need an expert view for the below code;

     public static string ExecuteScalarSingleValue(string dbPath, string tableName, string searchTerm, string searchColumnName,  string resultColumnName)
        {
            string connectionString = null;
            string sql = null;


            connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Mode=Read;Data Source="+ dbPath;

            
            sql = "Select ["+ resultColumnName + "] from ["+ tableName + "] Where [" + searchColumnName + "] = '" + searchTerm + "'";

            System.Data.OleDb.OleDbConnection cnn = new System.Data.OleDb.OleDbConnection(connectionString);
            try
            {
                cnn.Open();
                System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand(sql, cnn);
                // Get the value from the database
                string result = (string)cmd.ExecuteScalar();
                cmd.Dispose();
                cnn.Close();
                return result;
            }
            catch (Exception ex)
            {
                return null;
            }

        }

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It gives a warning like on attached picture.

It directs me to this page: https://docs.microsoft.com/en-us/visualstudio/code-quality/ca2100?view=vs-2019

But i couldn't be able to fix that warning.

Any help would be grateful.

DatabasesMicrosoft AccessC#SQL

Last Comment

Chris Stanyon

8/22/2022 - Mon

Chris Stanyon

12/23/2019

Because you're manually building your SQL string, it's possible that it's vulnerable to SQL Injection. Based on your code, it's impossible to tell where the arguments that make up your query come from. If they come from user input, then it's potentially dangerous.

The suggested code fix for that is to change to using a parameterised query. This removes the risk of SQL injection. On the page you linked to, scroll down and you'll find examples of how to run your query with parameters.

However, you won't be able to use the tableName, searchColumnName or resultColumnName as parameters (that's just not how it works).

Of course, if the method arguments are coming from a know, safe call, then you can just suppress the error and move on.

ste5an

12/23/2019

By restructuring your code, e.g. this should work:

public static string ExecuteScalarSingleValue(string databaseFilename, string tableName, string searchTerm, string searchColumnName,  string resultColumnName)
{
    const string CONNECTION_STRING = "Provider=Microsoft.ACE.OLEDB.12.0;Mode=Read;Data Source={0}";
    const string COMMAND_TEXT = "SELECT [{0}] FROM [{1}] WHERE [{2}] = @searchTerm;";

    string connectionString = string.Format(CONNECTION_STRING, databaseFilename);
    using (OleDbConnection connection = new OleDbConnection(connectionString)
    {
        connection.Open();
        string commandText = string.Format(COMMAND_TEXT, resultColumnName, tableName, searchColumnName);
        using (OleDbCommand command = new OleDbCommand(commandText, connection))
        {
            command.Parameters.Add(new OleDbParameter("@searchTerm", searchTerm));
            return (string)command.ExecuteScalar();
        }
    }
}

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p.s. you method name is suboptimal. A scalar is per definition a single value. Thus the name contains a redundant part.

Skale

12/23/2019

ASKER

Hi ste5an,

Problem continues as on attachment.

@Chris Stanyon you mean there's no additional solution, if you are trust your injection just supress it?

Your help has saved me hundreds of hours of internet surfing.

fblack61

ste5an

12/23/2019

hmm, what VS version? What target framework? This does not raise this warning:

namespace ConsoleCS
{
    using System;
    using System.Data.OleDb;

    public class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine(ExecuteScalarSingleValue(@"C:\Temp\myDatabase.accdb", "Table1", "1", "ID", "Payload"));

            Console.WriteLine("\nDone.");
            Console.ReadLine();
        }

        public static string ExecuteScalarSingleValue(string databaseFilename, string tableName, string searchTerm, string searchColumnName, string resultColumnName)
        {
            const string CONNECTION_STRING = "Provider=Microsoft.ACE.OLEDB.12.0;Mode=Read;Data Source={0}";
            const string COMMAND_TEXT = "SELECT [{0}] FROM [{1}] WHERE [{2}] = @searchTerm;";

            string connectionString = string.Format(CONNECTION_STRING, databaseFilename);
            using (OleDbConnection connection = new OleDbConnection(connectionString))
            {
                connection.Open();
                string commandText = string.Format(COMMAND_TEXT, resultColumnName, tableName, searchColumnName);
                using (OleDbCommand command = new OleDbCommand(commandText, connection))
                {
                    command.Parameters.Add(new OleDbParameter("@searchTerm", searchTerm));
                    return (string)command.ExecuteScalar();
                }
            }
        }
    }
}