In my previous posts, i have explained about different types of
SQL injections. Some times, when we try to retrieve data from
SQLi vulnerable websites, we end up with forbidden error. Today i will explain why you get such errors and how you can bypass such errors and perform successful attacks on websites. If you have not read my previous posts
and if you are new to SQLi, I would suggest you to read them before proceeding.
What is WAF? WAF stands for Web Application Firewall. In order to prevent the attacks such as
SQLiand XSS, administrators put Web Application Firewalls. These WAFs detect malicious attempts with the use of signature based filters and escapes defined within
a list of rules. As a result of this design, they are vulnerable and can be easily bypassed.
How it works??
When the WAF detects malicious attempts, our input URL gives a forbidden error as shown in the following figure.
Our aim is to bypass this error and need to retrieve data from the database using some special techniques. There are many methods to bypass WAF. In this tutorial, i am going to show you some basic methods. These methods are especially for beginners.
Methods To Bypass WAF Comments :-
Comments allow us to bypass a lot of the restrictions of Web application firewalls and to kill certain SQL statements to execute the attackers commands while commenting out the actual legitimate query.
http://vulnerablesite.com/detail.php?id=44 union all select 1,2,3,4,5—