What is SQL Injection? How does SQL Injection Attack work?

If the site doesn’t validate what the user is typing, someone can insert SQL-like things instead of typing normal login information.

So, the system mistakenly assumes everything is fine, logs in without logging in, sometimes exposing/losing entire tables of data.

What is SQL Injection?

SQL Injection is a very well-known and dangerous web security attack method. Through this, an attacker (hacker) can illegally access the website’s database. This attack typically involves stealing, modifying, or deleting database data by inserting malicious SQL code through user input.
If a website uses user input directly in a SQL query without properly validating it, then an opportunity created for SQL Injection attacks arises.

How does SQL Injection work?

Let’s say a website has a login form where username and password input is taken.
A typical SQL query might be:

SELECT * FROM users WHERE username = 'user' AND password = 'pass';

Now if a hacker enters a value like this in the input box:

' OR '1'='1

Then the query becomes like this:

SELECT * FROM users WHERE username = '' OR '1'='1';

So, here ‘1’=’1′ is always TRUE, that’s why the login system is bypassed.

Main causes of SQL Injection

You are coding in a very professional manner, but due to ignoring some small security measures, hackers can easily hack the server. Some common mistakes are responsible for SQL Injection. These mistakes make a website vulnerable to SQL Injection-

• Not Validating User Input Properly,
• Using Raw SQL Query,
• Not Using Prepared Statement
• Outdated or poor coding practices
• Directly displaying database error messages

Types of SQL Injection

• In-Band SQL Injection

This is the most common type. The attack and data response are received over the same channel.
Example:
Error-based SQL Injection
Union-based SQL Injection

• Blind SQL Injection

In this case, the data is not directly visible, but information is estimated through True/False or Delay.
Example:
Boolean-based Blind Injection
Time-based Blind Injection

• Out-of-Band SQL Injection

When data is sent from the database using another channel (DNS or HTTP). This is relatively less used.

Why SQL Injection is so dangerous?

What a hacker can do if SQL Injection is successful-

• Stealing usernames and passwords,
• Downloading entire databases,
• Modifying or deleting data,
• Gaining admin access,
• Destroying websites.

For this reason, SQL Injection is always included in the OWASP Top 10 Security Risks. So you can understand why articles are being written about it again and again.

Ways to Prevent SQL Injection

To avoid SQL Injection, the following points must be followed:

1. Use Prepared Statements: Prepared Statements treat input separately, so malicious code cannot run.
2. Input Validation & Sanitization: It is important to verify and clean all types of user input.
3. Use ORM: Using ORM in frameworks like Laravel, Django, and Hibernate reduces risk.
4. Hide Database Error: The error message cannot be displayed to the user.
5. Least Privilege Principle: Do not grant unnecessary permissions to database users.

Importance of learning SQL Injection

If you are a web developer, working with PHP, Laravel, Node.js, or WordPress, it is very important to know about SQL Injection. Because one small mistake can put your entire system at risk. SQL Injection can be easily prevented by following secure coding practices and conducting regular security tests.

So, SQL Injection is a serious web security vulnerability that can cause major damage if ignored. This risk can be greatly reduced by using proper coding standards, prepared statements, and input validation.
Being aware of SQL Injection is essential today to keep websites secure.