What is a SQL injection attack?

SQL injection is one of the most common and of course the most useful types of attacks on websites and web-based applications, which we will explain in this article.

One of the most common types of attacks on websites is the SQL injection attack, in which a hacker can obtain sensitive data and information from organizations. Although this attack applies to all data-driven applications that use the SQL database, it is often used to attack websites. But what exactly is SQL injection?

What is a SQL injection attack?

This attack is basically one of the code injection techniques that hackers use to enter their desired SQL statements (which is certainly malicious) into an input field to execute their so-called query. This attack is possible due to improper coding and vulnerabilities of web applications. In fact, improper programming allows the hacker to send a query to the database via the input field.

SQL injection attack risks

Hackers are constantly scrutinizing websites on the Internet until websites come vulnerable to SQL injection attacks. In fact, hackers use tools that automatically detect SQLi vulnerabilities on websites and try to use this trick to make a profit in the first place and in the most trivial way possible.

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A successful SQL injection attack can allow hackers to gain unauthorized access to sensitive data such as passwords. It is interesting to note that many cases of information leakage in recent years have been caused by SQL injections. Among the problems that SQLi attack causes are the following:

Stealing, altering, tampering with, and destroying sensitive data (e.g., user personal information, username, and password)
Change access privileges at different levels of applications, databases, and even operating systems
And…

Example of a SQL injection attack

So far we are familiar with the concept of SQL injection and its dangers, but in the following, we want to point to a simple example of this type of attack.

Look at the two lines of code below that have a UserId field that receives the user ID number and the next line displays all the user information with that number (UserId).

UserId = getRequestString (“UId”);
SQLQuerry = “SELECT * FROM Users WHERE UId =” + UserId;

A typical user enters their user number, for example, 105. But consider a hacker who knows the ins and outs of hacking and is looking for a way to infiltrate the system and has now found a way to obtain his information. So the hacker does his job by entering a clever input. So instead of 105, enter 105 OR 1 = 1 . So the value of the SQLQuerry statement now looks like this:

SELECT * FROM Users WHERE UserId = 105 OR 1 = 1;

Since 1 = 1 always has a value of True, this query provides the hacker with all the values ​​and all the rows and columns of the Users table. This table can contain important and sensitive information of users, including their passwords! Now you realize the simplicity of SQL injection attacks and the importance of preventing them? Of course, this example was just a simple SQL injection attack.