SQL injection: what is it and how to prevent it?

SQL injection: what is it and how to prevent it?
Photo by Caspar Camille Rubin / Unsplash

In this month of cybersecurity it is important to be aware of the different risks that exist in the online world and how to avoid being victims of an attack.

Just as we told you in our article last week, October is the month of cybersecurity and therefore, we will be offering you all the information you need to protect yourself in this online world. Today it's time to talk about "SQL Injection".

When we talk about SQL Injection, we are referring to a type of cyberattack in which a hacker inserts their own code into a website in order to break security measures and access protected data. Once inside, he can control the website's database and hijack user information; but, before delving into this type of attack, it is necessary to explain what SQL is.

It is a structured query language, that is, a type of programming language that allows you to manipulate and download information from a database and also has the ability to do advanced calculations and algebra. Given its strong connection to relational model theory, SQL is a recordset-oriented high-level language. This implies that a single SQL command can be equivalent to tens or hundreds of lines of code that would have to be used in a lower level record-oriented language.

As a result, SQL makes it faster and easier to define and manipulate database objects, thus enabling greater development efficiency and productivity.

SQL injection

SQL injection is an extremely common type of cyber attack, especially on PHP and ASP applications. In fact, code injection (which includes SQL injection) tops the OWASP list of the 10 biggest web application security risks.

This is due to three reasons, mainly:

  • SQL databases are widely used.
  • Generally, these systems contain information that is extremely attractive to hackers (user account data, credit card numbers, administrator login credentials, etc.)
  • The code injection vulnerability is a widespread security flaw in web applications, especially those with legacy code.

SQL injection is an old technique. It is commonly considered to have been first raised in 1998. Since then, malicious actors have used SQL injection attacks to wreak havoc on all kinds of companies and institutions, from the World Trade Organization to Yahoo. In a particularly big crackdown in 2013, hackers found a way to trick Google's web crawlers into running SQL injection attacks simply by posting SQL injection URLs to websites they controlled. When crawling these websites, Google's spiders followed the malicious links, unknowingly becoming SQL injection attack vectors on the targets.

These types of attacks are easy to perpetrate, and the consequences can be devastating for the victim. Therefore, it is not surprising that it remains such a popular method among hackers. A successful SQL injection attack can allow the attacker to:

  • Extract and disclose sensitive information.
  • Delete the content of a database.
  • Manipulate transactions.
  • Forge identities.
  • Force privilege escalation and become an administrator of the database server.

To carry out these types of attacks, cybercriminals use bots to look for SQL injection vulnerabilities in web applications. Once a vulnerability has been identified, attackers enter malicious commands. They will often try different variations to try to figure out what they can get the database to do.

SQL Server icon in 3D. My 3D work may be seen in the section titled "3D Render."
Photo by Rubaitul Azad / Unsplash

How to prevent SQL injection attacks?

The key principles to help protect web sites and applications are the following:

  1. Train the staff: make the team responsible for the web application aware of the risks related to SQLi (SQL injection) and provide the necessary training for all users based on their positions and responsibilities.
  2. Maintain control of user input: any user input used in an SQL query creates a risk. It is recommended that you grant accounts that connect to the SQL database only the minimum necessary privileges.
  3. Staying up-to-date is a priority: It's important to use the latest version of your development environment to maximize protection, as older versions may lack security features. Make sure to install the latest software and security patches when they become available.
  4. Continuously analyze web applications: Use comprehensive application performance management tools. Regularly scanning web applications allows you to identify and address potential vulnerabilities before they cause serious damage.
  5. Using a firewall: a web application firewall (WAF) is often used to filter SQLi as well as other online threats.

As the true targets of SQLi attacks are enterprises, they face a much more diverse set of threats. When a hacker breaks into a database, he can take several actions and, once the event is disclosed, the affected company must prepare to face the damage to its public image and minimize it. Some of the damages that an attack of this type can cause are:

  • A hacker can easily wreak havoc on a company by deleting its database or smashing its website.
  • Many SQLi attacks are aimed at stealing sensitive data such as trade secrets, privileged information, protected intellectual property, and often user or customer information.
  • A hacker could use the contents of a compromised database to gain access to other parts of a company's internal network. In the end, the entire network may be at risk.
  • After suffering the effects of an SQLi attack, it can be difficult for a company to regain the trust of its customers and the general public.

As we always tell you, at e•saurio we take security very seriously and we want to prevent you from becoming another victim of unscrupulous people who, hidden behind a computer, cause losses that are often irreparable.

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