Online security is an issue that we always need to improve, and one of the most common threats that web developers face is SQL injection. If you have a website, no matter how big or small, it is vital that you understand what SQL injections are and how to protect your site against them.
In this article we will explain in a simple way what SQL injections are and how to avoid them, giving you practical tips to protect your website.
What is an SQL injection?
SQL injections are a type of computer attack that exploits vulnerabilities in web applications to manipulate databases. SQL (Structured Query Language) is a language used to manage databases, and SQL injections occur when an attacker enters malicious SQL commands into the input fields of a website.
These commands can spoof the database and ultimately provide unauthorised access to sensitive information or even allow data to be deleted.
The dangers of SQL injections
SQL injections can have serious consequences for a website and its users. Some of the most common risks include:
- Information theft: Attackers can access sensitive data, such as passwords, personal and financial information.
- Modification or deletion of data: Data stored in the database may be maliciously altered or deleted, which may cause irreparable damage.
- Denial of Service (DDoS) attacks: Attackers can use SQL injections to slow down or paralyse a website, negatively affecting the user experience and the company’s reputation.
- Executing commands on the server: In extreme cases, attackers can execute commands on the web server, giving them complete control over the system.
How to protect your website against SQL injections
Input validation
Input validation is a crucial step in preventing SQL injections. You must ensure that data entered by users meets certain criteria before it is processed. This includes verifying that only allowed characters are entered in the input fields.
Use prepared parameters
A prepared parameter is a database feature that allows SQL commands to be separated from the input data. Instead of embedding the data directly into an SQL query, placeholders are used that are safely filled with the values provided by the user.
Escape user input
Escaping user input means that special characters, such as single quotes, are treated in such a way that they are not interpreted as SQL commands.
Apply the principle of least privilege
When setting up database access accounts, make sure they have the minimum privileges necessary. This will limit the impact of a potential attack, as cybercriminals will only have access to essential functions.
Update and patch your applications
Keep your applications and systems up to date with the latest security fixes. Developers often release patches to address known vulnerabilities, so it is important to apply these updates.
Monitor and log
Set up logging and monitoring systems to detect unusual activity on your website. It is always better to prevent an attack or detect it early to minimise damage.
Tools and programming languages
When implementing SQL injection protection measures, it is important to have the right tools and languages.
Secure programming languages
Some programming languages, such as Python and Ruby, are designed with features that reduce the likelihood of SQL injections. Using these languages can help protect your website at its core.
Secure frameworks
Web frameworks, such as Ruby on Rails and Django, provide additional layers of security by processing user input and generating SQL queries. Using a well-established framework can simplify the implementation of security measures.
Security scanning tools
There are security scanning tools, such as OWASP ZAP and Nessus, that can help you identify and fix vulnerabilities in your website. These tools scan your application for SQL injections and other threats.
Security libraries
Security libraries, such as Hibernate for Java or Sequelize for Node.js, can help you implement ready-made parameters and other security measures in your applications.
Additionals tips
- Perform security testing: Conduct regular security tests on your website to identify and fix potential vulnerabilities before attackers exploit them.
- Educate your team: Make sure your development team understands security threats and is aware of best practices to prevent them.
- Keep backups: Make regular backups of your data so that you can recover in the event of a successful attack.
- Restrict physical and logical access to the server: Make sure that only authorised persons have access to the server hosting your database.
- Keep your users informed: If a security incident occurs, notify your users immediately and provide them with information on how to protect their accounts.
SQL injections are a serious threat to any website that relies on a database. The good news is that there are effective measures to protect your site and your data. By understanding how to avoid SQL injections and applying good security practices, you can significantly reduce the risk of an attack.