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Last revision (mm/dd/yy): 07/7/2014
Introduction
'Ey, Howzit? One SQL Injection is da moddah of all web vulnerabilities. Fo' real! So much so that it's da #1 item in da OWASP Top 10. It represents a serious threat because SQL Injection allows evil attacker code to change da structure of a web application's SQL statement in a way that can steal data, modify data, or potentially facilitate command injection to da underlying OS.
Dis cheat sheet is a derivative work of da SQL Injection Prevention Cheat Sheet. Mahalos yeah fo' checking out dis place. Shoots!
Parameterized Query Examples
SQL Injection is best prevented through the use of parameterized queries. Da following chart demonstrates, with real-world code samples, how to build parameterized queries in most of da common web languages. Da purpose of these code samples is to demonstrate to da web developer how to avoid SQL Injection when building database queries within a web application.
Prepared Statement Examples
| Language - Library
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Parameterized Query
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| Java - Standard
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String custname = request.getParameter("customerName");
String query = "SELECT account_balance FROM user_data WHERE user_name = ? ";
PreparedStatement pstmt = connection.prepareStatement( query );
pstmt.setString( 1, custname);
ResultSet results = pstmt.executeQuery( );
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| Java - Hibernate
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//HQL
Query safeHQLQuery = session.createQuery("from Inventory where productID=:productid");
safeHQLQuery.setParameter("productid", userSuppliedParameter);
//Criteria API
String userSuppliedParameter = request.getParameter("Product-Description"); // Dis should REALLY be validated too
// perform input validation to detect attacks
Inventory inv = (Inventory) session.createCriteria(Inventory.class).add
(Restrictions.eq("productDescription", userSuppliedParameter)).uniqueResult();
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| .NET/C#
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String query = "SELECT account_balance FROM user_data WHERE user_name = ?";
try {
OleDbCommand command = new OleDbCommand(query, connection);
command.Parameters.Add(new OleDbParameter("customerName", CustomerName Name.Text));
OleDbDataReader reader = command.ExecuteReader();
// …
} catch (OleDbException se) {
// error handling
}
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| ASP.NET
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string sql = "SELECT * FROM Customers WHERE CustomerId = @CustomerId";
SqlCommand command = new SqlCommand(sql);
command.Parameters.Add(new SqlParameter("@CustomerId", System.Data.SqlDbType.Int));
command.Parameters["@CustomerId"].Value = 1;
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| Ruby - ActiveRecord
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# Create
Project.create!(:name => 'owasp')
# Read
Project.all(:conditions => "name = ?", name)
Project.all(:conditions => { :name => name })
Project.where("name = :name", :name => name)
# Update
project.update_attributes(:name => 'owasp')
# Delete
Project.delete(:name => 'name')
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| Ruby
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insert_new_user = db.prepare "INSERT INTO users (name, age, gender) VALUES (?, ? ,?)"
insert_new_user.execute 'aizatto', '20', 'male'
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| PHP - PDO
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$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (:name, :value)");
$stmt->bindParam(':name', $name);
$stmt->bindParam(':value', $value);
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| Cold Fusion
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<cfquery name = "getFirst" dataSource = "cfsnippets">
SELECT * FROM #strDatabasePrefix#_courses WHERE intCourseID =
<cfqueryparam value = #intCourseID# CFSQLType = "CF_SQL_INTEGER">
</cfquery>
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| Perl - DBI
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my $sql = "INSERT INTO foo (bar, baz) VALUES ( ?, ? )";
my $sth = $dbh->prepare( $sql );
$sth->execute( $bar, $baz );
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Stored Procedure Examples
Da SQL you write in your web application isn't da only place that SQL injection vulnerabilities can be introduced. If you are using Stored Procedures, and you are dynamically constructing SQL inside them, you can also introduce SQL injection vulnerabilities. To ensure dis dynamic SQL is secure, you can parameterize dis dynamic SQL too using bind variables. Here are some examples of using bind variables in stored procedures in different databases:
| Language - Library
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Parameterized Query
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| Oracle - PL/SQL
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Normal Stored Procedure - no dynamic SQL being created. Parameters passed in to stored procedures are naturally bound to their location within da query without anything special being required.
PROCEDURE SafeGetBalanceQuery(
UserID varchar, Dept varchar) AS BEGIN
SELECT balance FROM accounts_table WHERE user_ID = UserID AND department = Dept;
END;
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| Oracle - PL/SQL
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Stored Procedure Using Bind Variables in SQL Run with EXECUTE. Bind variables are used to tell da database that da inputs to dis dynamic SQL are 'data' and not possibly code.
PROCEDURE AnotherSafeGetBalanceQuery(
UserID varchar, Dept varchar) AS
stmt VARCHAR(400); result NUMBER;
BEGIN
stmt := 'SELECT balance FROM accounts_table WHERE user_ID = :1
AND department = :2';
EXECUTE IMMEDIATE stmt INTO result USING UserID, Dept;
RETURN result;
END;
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| SQL Server- Transact-SQL
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Normal Stored Procedure - no dynamic SQL being created. Parameters passed in to stored procedures are naturally bound to da location within da query without anything special being required.
PROCEDURE SafeGetBalanceQuery(
@UserID varchar(20),
@Dept varchar(10)) AS BEGIN
SELECT balance FROM accounts_table WHERE user_ID = @UserID AND department = @Dept
END
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| SQL Server- Transact-SQL
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Stored Procedure Using Bind Variables in SQL Run with EXEC. Bind variables are used to tell da database that da inputs to dis dynamic SQL are 'data' and not possibly code.
PROCEDURE SafeGetBalanceQuery(@UserID varchar(20),
@Dept varchar(10)) AS BEGIN
DECLARE @sql VARCHAR(200)
SELECT @sql = 'SELECT balance FROM accounts_table WHERE '
+ 'user_ID = @UID AND department = @DPT'
EXEC sp_executesql @sql,
'@UID VARCHAR(20), @DPT VARCHAR(10)',
@UID=@UserID, @DPT=@Dept
END
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References
Authors and Primary Editors
Jim Manico - jim [at] owasp.org
Dave Wichers - dave.wichers [at] aspectsecurity.com
Neil Matatal - neil [at] owasp.org
Other Cheatsheets
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