What is SQL Injection

By: Emiley J.  

SQL Injection is a method in which an attacker inserts malicious code into queries that run on your database. Have a look at this example:


$query = "SELECT login_id FROM users WHERE user='$user' AND pwd='$pw'";



Voilà! Anyone can log in as any user, using a query string like http://example.com/login.php?user=admin'%20OR%20(user='&pwd=')%20OR%20user=', which effectively calls the following statements:


$query = "SELECT login_id FROM users WHERE user='admin' OR (user = '' AND pwd='') OR user=''";



It’s even simpler with the URL http://example.com/login.php?user=admin'%23, which executes the query SELECT login_id FROM users WHERE user='admin'#' AND pwd=''. Note that the # marks the beginning of a comment in SQL.

Again, it’s a simple attack. Fortunately, it’s also easy to prevent. You can sanitize the input using the addslashes() function that adds a slash before every single quote ('), double quote ("), backslash (\), and NUL (\0). Other functions are available to sanitize input, such as strip_tags().


Archived Comments

1. Asking questions are genuinely pleasant thing if you are not understanding anything entirely, except
View Tutorial          By: http://geschenkefuermaenner.info at 2017-04-16 02:58:49

2. Debrakerne
View Tutorial          By: Debrakerne at 2017-03-16 03:55:45

Most Viewed Articles (in MySQL )

Latest Articles (in MySQL)

Comment on this tutorial