Solved

Prevent SQL Injection

Posted on 2009-05-19
5
614 Views
Last Modified: 2012-05-07
Hi to all,

I have the code below and I want to make sure that it is the best way to try and prevent SQL injection.

I am using Free text for my search in order to let the user type in a description of the item. I am also using full text search on that table.

What would I need to do more to prevent successful attacks on my DB?
Any suggestion would be welcomed.

Thanks
Public Shared Function LoadItemSearch(ByVal ItemDescription As String) As SqlDataReader
            Dim connection As New SqlConnection _
            (RMSConnectionString.StoreCon.ConnectionString)
 
            Dim SQLCommand As SqlClient.SqlCommand
            Dim strSQL As String
            connection.Open()
            Try
 
                strSQL = "Select  Item.ID, Item.ItemLookupCode, UPPER(Item.Description) As Description,    " & _
                            "Item.ExtendedDescription AS ItemDescription, Item.PictureName  " & _
                            " FROM Item INNER JOIN Department ON Item.DepartmentID = Department.ID    " & _
                            " WHERE (Item.Inactive = 0) And Item.WebItem = 0 And Item.ItemType <> 7 And Item.Quantity > 0   " & _
                            " And FreeText(Description, @Item) " & _
                            " ORDER BY SubDescription2 DESC"
 
                SQLCommand = New SqlClient.SqlCommand(strSQL, connection)
                SQLCommand.Parameters.Add(New SqlParameter("@Item", Data.SqlDbType.VarChar)).Value _
                = ItemDescription
               
                Dim MyReader As SqlDataReader = SQLCommand.ExecuteReader
                Return MyReader
                connection.Close()
                SQLCommand.Dispose()
                connection.Dispose()
            Catch Exp As SqlClient.SqlException
                Throw Exp
            End Try
        End Function

Open in new window

0
Comment
Question by:ALawrence007
5 Comments
 
LVL 15

Assisted Solution

by:mohan_sekar
mohan_sekar earned 125 total points
ID: 24423138
0
 
LVL 2

Accepted Solution

by:
d1rtyw0rm earned 200 total points
ID: 24423197
You are doing great by using parameterised queries.

This is where the SQL Command uses a parameter instead of injecting the values directly into the command. The particular second-order attack above would not have been possible if parameterised queries had been used.

-----------------------------------------------------------

Stored Procedures add an extra layer of abstraction in to the design of a software system. This means that, so long as the interface on the stored procedure stays the same, the underlying table structure can change with no noticeable consequence to the application that is using the database. This layer of abstraction also helps put up an extra barrier to potential attackers. If access to the data in SQL Server is only ever permitted via stored procedures, then permission does not need to be explicitly set on any of the tables. Therefore, none of the tables should ever need to be exposed directly to outside applications. For an outside application to read or modify the database, it must go through stored procedures. Even though some stored procedures, if used incorrectly, could potentially damage the database, anything that can reduce the attack surface is beneficial.

Stored procedures can be written to validate any input that is sent to them to ensure the integrity of the data beyond the simple constraints otherwise available on the tables. Parameters can be checked for valid ranges. Information can be cross checked with data in other tables.

--------------------------------------------------------------------

Encrypt sensitive data.
Access the database using an account with the least privileges necessary.
Install the database using an account with the least privileges necessary.
Ensure that data is valid.
Do a code review to check for the possibility of second-order attacks.
Use parameterised queries.
Use stored procedures.
Re-validate data in stored procedures.
Ensure that error messages give nothing away about the internal architecture of the application or the database.


http://unixwiz.net/techtips/sql-injection.html

0
 
LVL 21

Assisted Solution

by:Tapan Pattanaik
Tapan Pattanaik earned 125 total points
ID: 24423204
0
 
LVL 48

Assisted Solution

by:jpaulino
jpaulino earned 50 total points
ID: 24426284
You have allot of links provided already, but basically you need to use Stored Procedures with parameters passed to him, to ensure that you're SQL Injection safe.
0
 

Author Closing Comment

by:ALawrence007
ID: 31583047
Thank you SO much guys!
I added Stored procs to make my site more secure
0

Featured Post

DevOps Toolchain Recommendations

Read this Gartner Research Note and discover how your IT organization can automate and optimize DevOps processes using a toolchain architecture.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
SQL Help 27 40
SQL Replication question 9 41
Help creating a spatial object in SQL Server 4 20
SQL View nearest date 5 34
It was really hard time for me to get the understanding of Delegates in C#. I went through many websites and articles but I found them very clumsy. After going through those sites, I noted down the points in a easy way so here I am sharing that undeā€¦
This article shows how to deploy dynamic backgrounds to computers depending on the aspect ratio of display
Using examples as well as descriptions, and references to Books Online, show the documentation available for date manipulation functions and by using a select few of these functions, show how date based data can be manipulated with these functions.
Viewers will learn how to use the SELECT statement in SQL to return specific rows and columns, with various degrees of sorting and limits in place.

813 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now