Last Updated on 19 April 2023 by Daniel

1. Introduction
SQL injection is a type of attack that allows an attacker to execute malicious SQL code on a database. This code can be used to view, modify, or delete data from the database. SQL injection attacks are a serious threat to any website that relies on a database for its operation.
In order to protect your website from SQL injection attacks, you need to understand how they work and what you can do to prevent them. Keep reading to learn more about SQL injection attacks and how you can protect your website against them.

2. What is SQL Injection?
SQL injection is a type of attack that allows an attacker to execute malicious SQL code on a database. This code can be used to view, modify, or delete data from the database.
In a SQL injection attack, the attacker sends malicious SQL code to the web application. When this code is executed, it allows the attacker to gain access to the database, either for malicious intent or for data exfiltration.
Because SQL injection attacks can be used to gain access to sensitive data, they can be used to commit identity theft, credit card fraud, or other forms of data theft. They also can be used to delete data, or make changes to the website.
SQL injection attacks are extremely dangerous and can be difficult to detect and protect against. To prevent SQL injection attacks, websites should be built to protect against malicious code and test input validation.

3. How do SQL Injection Attacks Work?
SQL Injection attacks work by exploiting vulnerabilities in a web application’s code or in the database itself. An attacker can send malicious requests to the web application with specially crafted SQL queries. The web application then processes the request and passes it on to the database, where the malicious code is executed.
The malicious code can be used to gain access to the database and gain access to sensitive data stored within the database. It can also be used to modify, delete, or insert data into the database. The attacker can also use the malicious code to gain administrative privileges on the website or on the server itself.
SQL injection attacks are difficult to detect and protect against. To minimize the risk of SQL injection attacks, developers should take certain steps to protect their websites from malicious code. They should ensure that web applications are properly tested and use input validation techniques to catch and prevent any malicious input. Additionally, best security practices such as using strong passwords, using VPNs, restricting access to systems, and monitoring logs should be in place.

4. How to Prevent SQL Injection Attacks?
Preventing an SQL injection attack starts with secure coding practices and secure programming languages. Make sure to use parameterized queries and stored procedures which can help reduce the chances of SQL Injection.
Web Application Firewalls (WAFs) provide an extra layer of security against SQL Injection attacks by detecting and blocking suspicious activity from entering a website. The WAF scans HTTP requests and blocks any requests that include malicious code.
Whitelisting input is also incredibly effective for preventing SQL injection attacks. This means only allowing certain strings or requests that are proven safe and blocking any other requests. For example, allowing only numbers for a phone number field in a web form.
Other methods for protection against SQL Injection include data encryption, setting up multiple layers of access control, and auditing of user accounts periodically. All of these methods can help to protect your web app and databases from unwanted injections.

5. Filtering Input
Input filtering is all about validating input data before it is stored in the database or executed. Validating the data helps to filter out malicious code before it penetrates your server.
Input filtering techniques include:
– Implementing Tight Access Controls: Allowing only certain types of input from users who have certain levels of access. This helps ensure only trusted users are allowed to enter data, and any suspicious input is filtered out.
– Inspecting the Input Data: This involves closely inspecting each piece of user data that is entered and matching it against a set of pre-defined rules. If the data does not match the rules, it is filtered out.
– Removing Unnecessary Data: Data is stripped of all unnecessary characters that do not match the type of data expected. This helps to prevent any possible malicious code from getting through.
– Sanitizing Data: When user data is inputted, it is important to ensure it has been “cleaned” or sanitized. This means that any characters that would lead to an SQL injection attack are removed or escaped.

6. Escaping Output
One of the most effective ways to protect your website from SQL injection attacks is to escape your output.
Escape Output is an umbrella term for a variety of techniques that help protect against malicious user input by transforming the data before it is sent back to the user. These techniques usually involve parsing through the data and, when necessary, encoding or validating the data before it is returned.
With output escaping, the output data is transformed so that any malicious code is rendered harmless, meaning it will not be executed. This means that if a hacker inputs malicious data, it will be transformed into a harmless string of characters before it is returned.
Output escaping is an effective way to protect your website from SQL injection attacks. It doesn’t take a lot of time or effort to implement, and it can be the difference between a safe website and one that is vulnerable to attack.

7. Sanitizing Queries
In order to further prevent SQL injection attacks, it is essential to sanitize queries. Sanitizing queries is a way of ensuring that all user input is valid and does not contain malicious code before it is accepted by the database.
There are a few different methods for sanitizing user input, such as validating the data type, length, and format of the data. The data should also be checked for malicious keywords such as “DROP TABLE”. If any malicious code is found, it should be removed or replaced before it is accepted into the database.
Another way to sanitize user input is to use prepared statements.
A prepared statement is a query that is prepared by a database system. The statement is pre-compiled and stored in a server so that it can be reused without having to go through the compilation process every time it is used. This eliminates the need to include user input directly in the query and prevents SQL injection attacks.
Sanitizing queries is an effective way to defend against SQL injection attacks. If implemented properly, it can almost completely eliminate the risk.

8. Conclusion
SQL injection attacks are a threat to any website. As a website owner, you have the obligation to protect your website and the information of your customers from these hackers.
Fortunately, there are a number of effective measures you can take to prevent SQL injection attacks. All of the steps, from using parameterized queries and web application firewalls to encrypting data and sanitizing queries, can be implemented in one way or another to improve the security of your website.
At the same time, it is also essential to be constantly monitoring your website for any suspicious activity or malicious intent. Through timely detection, you can take immediate steps to prevent a SQL injection attack and protect your website and customers.