SQL injection is a popular method amongst hackers that can cause major problems within an organization. Through SQL injection, an attacker can easily bypass various security measures like authentication. In this article, we will take a closer look at how you can prevent it.
What is SQL injection attack?
Even though they have been around for a while, SQL injections still pose a serious danger to web applications. That is why it is very important to get a firm grasp of what an SQL injection attack is, and how it can be prevented.
An SQL injection is a technique employed by hackers. Through an SQL injection, an attacker is able to insert adversary SQL commands that can damage data-driven applications and web pages.
Through a successful SQL injection attack, the attacker gains access to an organization’s servers, networks and database. As a result, they can steal data or change entries. Moreover, they can even lock you out of your network.
What are the types of SQL injection attacks?
There are various ways to conduct an SQL injection attack. As a result, it is possible to name at least ten different SQL injection attack types. Traditionally, we can classify the types of SQL injection in accordance with order of injection, input data type, server response and data extraction channel.
Within the framework of order of injection, there are two types of SQL injection attacks: First order injection and second order injection. In the first order injection, the attacker enters a malicious string and commands it to be executed immediately. In the second order injection attack, the attacker inputs a malicious string that is rather resistant and stealthy. This string is executed when a trigger activity is realized.
Similar to the order of injection, there are two sub-categories of input data type classification: String based injection and integer based injection. A string based injection differs from an integer based injection in the ability to display the results of the SQLi query. In string based injection, it is not possible to see the results of an injection in real time.
If we were to use server response as a criterion for the classification of SQL injections, we can categorize injections as error based SQLi and blind based SQLi. In error based SQLi, the attacker exploits the error messages created by the data server. In blind based SQLi, the attacker employs a method that aims to exploit the database through asking true or false questions.
Within the framework of data extraction channel, there are two categories of SQL injections: in band and out of band. When an attacker prefers in-band injection, they use the same channel of communication for launching the SQLi attack and gather the results of their attack. In opposition, out of band SQLi attack occurs when the attacker exploit two different channels for launching the attack and gathering the results.
How can SQLi attacks be prevented?
There are various measures you can take in order to protect your organization from SQL injection attacks.
- Refrain from using dynamic SQL
- Employ a proper sanitization protocol for user-provided inputs
- Make use of a strong WAF to protect the web applications that have access to important databases
- Keep all the databases and security measures updated
- Don’t make database error messages available for the user