Formatted SQL queries can be difficult to maintain, debug and can increase the risk of SQL injection when concatenating untrusted values into the query. However, this rule doesn’t detect SQL injections (unlike rule {rule:csharpsquid:S3649}), the goal is only to highlight complex/formatted queries.

Ask Yourself Whether

There is a risk if you answered yes to any of those questions.

Recommended Secure Coding Practices

Sensitive Code Example

public void Foo(DbContext context, string query, string param)
{
    string sensitiveQuery = string.Concat(query, param);
    context.Database.ExecuteSqlCommand(sensitiveQuery); // Sensitive
    context.Query<User>().FromSql(sensitiveQuery); // Sensitive

    context.Database.ExecuteSqlCommand($"SELECT * FROM mytable WHERE mycol={value}", param); // Sensitive, the FormattableString is evaluated and converted to RawSqlString
    string query = $"SELECT * FROM mytable WHERE mycol={param}";
    context.Database.ExecuteSqlCommand(query); // Sensitive, the FormattableString has already been evaluated, it won't be converted to a parametrized query.
}

public void Bar(SqlConnection connection, string param)
{
    SqlCommand command;
    string sensitiveQuery = string.Format("INSERT INTO Users (name) VALUES (\"{0}\")", param);
    command = new SqlCommand(sensitiveQuery); // Sensitive

    command.CommandText = sensitiveQuery; // Sensitive

    SqlDataAdapter adapter;
    adapter = new SqlDataAdapter(sensitiveQuery, connection); // Sensitive
}

Compliant Solution

public void Foo(DbContext context, string query, string param)
{
    context.Database.ExecuteSqlCommand("SELECT * FROM mytable WHERE mycol=@p0", param); // Compliant, it's a parametrized safe query
}

See