For modern information systems, data is an essential component. Database powered websites are used by various companies to get and store customer data. Structured Query Language, also known as SQL, is used to manipulate and retrieve data from the database.
A SQL Injection attack damages the dynamic SQL statements to affect some parts of the statement or adds a condition that is always true. It attacks the design flaws in poorly structured application and executes a malicious SQL code.
The guide below will teach you how to create a SQL Injection and attack vulnerable web applications.
How does a SQL Injection work and its impact
The SQL Injection definition tells us that it is a vulnerability that allows a cyber attacker to interfere and change the queries that a website makes to its database. He can view data that is usually not available to view or edit. It may include user data and other confidential data of the application.
The attacker gets the ability to modify, edit, or even delete the data, which can cause widespread effects on the application’s running and behavior. He can enhance the SQL Injection to exploit the back-end server or even start a denial-of-service (DoS) attack.
A successful attack gives illegal access to the application’s sensitive information, including passwords, customer’s personal information, credit/debit card information, etc. In recent years, many high-profile data thefts have taken place due to SQL Injection attacks.
Some attackers can gain entry into the back-end systems and stay there for long without being unnoticed. This results in the application’s performance dropping and can cause reputational and efficiency damage.
How to create a SQL Injection and various types
There are many SQL Injection attacks, techniques, and vulnerabilities in different situations. Let us know about some common SQL Injection types and their features.
Subverting application logic
Think of an application in which users use a password and username to log in. If the username is wiener and the password is bluecheese, the application runs a check by using the query: SELECT * FROM users WHERE username = 'wiener' AND password = 'bluecheese.'
The attacker can use a SQL comment to login without a password and remove the password check from the WHERE clause. He can submit the query with the username ‘administrator’ and a blank password. This will allow him to login without any password with the username ‘administrator.’
When a SQL query results in a return within the application's response, an attacker can use SQL Injection to gather data from other tables of the database. You need to use the UNION keyword and run an extra SELECT query, which will allow you to add results to the original query. For example, SELECT name, description FROM products WHERE category = 'Gift.' The attacker should input this: UNION SELECT username, password FROM users--. With this, the application will also return usernames and password along with other information
Blind SQL Injection
In blind SQL injections, the application does not return results, details, or any other data. In this, an attacker can change the query’s logic to alter the application’s response. He can even trigger a deliberate time delay that can deduce the truth based on the application’s response time.
By using OAST methods, an attacker can create out-of-band network interaction. When other techniques are not working, this will come to the rescue and let you exfiltrate data through the network.
Examining the database
When you detect a small SQL Injection vulnerability, it is fine to gather some knowledge about the database, which often helps in exploiting the application further. Find out about the version of the database, and you should know about the database type so that you use the correct techniques.
How to prevent SQL Injection?
If you run a database powered organization or application, you should know how to deal with a SQL Injection attack. The following measures will teach you how to prevent SQL Injection and stay safe.You should never trust user input and analyze all data before using it in SQL statements.
Use stored procedures that encapsulate SQL statements and handle inputs as parameters. Only certain accounts should be given the necessary access to connect to the database.Error messages should not reveal where it has occurred or any other sensitive details.
SQL Injections are widely being used to attack vulnerable applications and steal or manipulate an application’s data. It affects the performance and poses a threat to the security of the application and its data. In the above guide, we discussed the basics of a SQL Injection and how to create it.
Keep yourself informed and updated so that you do not fall victim to an attack in the future. Keep yourself prepared to prevent any SQL Injection attack.