Skip to main content


Showing posts from November, 2012

How to prevent mysql sleep injections?

Recently, we faced an issue with website which was developed around one year back. One hacker successfully tried to slow the website using sleep injection . Although we were using precautions like mysqli_real_escape_string() for escaping SQL string syntax correctly . Let’s see why this happened then and what are the solutions? We were using following code to get product id passed through query string. $id   = mysqli_real_escape_string($con , (isset($_REQUEST['id']) ? $_REQUEST['id'] : 0)); $qry = "Select * from products where id = ".$id; but hacker tried to change the the query string as :  ?id=3 and sleep(4) and query becomes Select * from products where id = 3 and sleep(4); And it started taking around 4+seconds to run the query. So in this way website become too slow. We were trying to figure out the possible and the best solution. After spending some time we noticed that although we were using mysql