How to Prevent Against WordPress SQL Injection Attacks [The Right Way]

Imagine waking up to find your WordPress site compromised, user data stolen, and your hard work undone by a single malicious attack. This nightmare scenario is true for many website owners who fall victim to WordPress SQL injection attacks.

WordPress SQL injection attacks are among the most prevalent and damaging security threats.

According to Statista, “SQL injection attacks account for 23% of all web application security incidents.”

But don’t worry! There are plenty of security measures that you can use to protect your website from WordPress SQL injection attacks. 

In this article, we will explain What an SQL injection attack is and how it works, as well as how to detect and remove SQL injections from your site safely.

Ready? Let’s begin!

What is an SQL injection in WordPress?

To understand WordPress SQL Injection, let’s first understand what SQL is.

SQL, short for ‘Structured Query Language,’ is a programming language that most data analysts and developers embed with the Java programming language to interact with major SQL database systems such as Oracle or MS SQL Server.

In WordPress, SQL injection is a type of cyber attack that targets the database of a WordPress site. This usually happens when a hacker inserts malicious SQL code into an SQL query through an input field, which can be anything from a search bar to a login form.

For example, instead of a regular login query, an attacker might input an SQL statement that bypasses authentication and gives them access to the admin panel.

If an attacker successfully exploits the WordPress SQL injection vulnerability, they can retrieve sensitive information, modify or delete data, and even gain administrative access to the site.

How Does WordPress SQL Injection Work? 

As we told you, in WordPress SQL injection, a hacker exploits vulnerabilities in your website’s code. These vulnerabilities allow hackers to insert malicious SQL code into your WordPress database queries.

Here’s a step-by-step breakdown of how a WordPress SQL injection attack typically unfolds:

Step #1. Identifying a Vulnerable Input Field: The attacker first identifies an input field on your site that doesn’t fully validate or sanitize user inputs. This could be a search bar, comment section, or login form.

Step #2. Malicious SQL Code Insertion: Once the attacker finds a vulnerable input field, they insert malicious SQL code into it. For instance, instead of a regular search query, they might input SQL commands designed to manipulate the database.

Step #3. SQL Code Execution: If your site fails to process input properly, the database executes the malicious SQL code. This can result in various harmful actions, such as retrieving confidential information, altering data, or deleting important records.

Step #4. Gaining Unauthorized Access: In more severe cases, the attacker can use SQL injection to bypass authentication mechanisms. This allows them to gain administrative access to your WordPress site, giving them control over your content and user data.

Step #5: Stealing or Damaging Data: With access to the database, the attacker can steal sensitive information, such as user credentials, financial data, or personal details. They can also corrupt or delete data, causing significant damage to your site’s functionality and reputation.

Examples of Real Life WordPress SQL Injection Attacks

SQL injection attacks have caused significant damage to many high-profile organizations. Here are some notable examples of such attacks on WordPress sites and related services:

1. Over $100 Million Payment Card Records Stolen

In 2009, Heartland Payment Systems, a company providing payment processing and payroll services, suffered a massive SQL injection attack. This breach compromised over 100 million payment card records. Because of this, the company had to pay more than $200 million in compensation. Additionally, the company’s stock value dropped by 77%, which shows how damaging an SQL Injection attack can be.

2. Data Theft on 5 Million Websites

In 2021, WooCommerce and its block feature plugin were vulnerable to SQLi. That security flaw exposed data on approximately 5 million websites to potential theft via SQL injection.

3. Freepik SQL Injection Incident

Freepik is one of the biggest leading providers of free online graphic resources. In 2020, its Freepik graphic resources app and Flaticon icon database platform was attacked with SQL injection. This breach allowed hackers to steal emails and password hashes of 8.3 million Freepik and Flaticon users.

With 18 million monthly unique users, the attack on Freepik showed the extent of the damage that SQL injection attacks can have on a large-scale platform.

Types of SQL Injection Attacks

There are two main types of SQL injection attacks:

• In-Band SQL Injection
• Blind SQL Injection

1. In-Band SQL Injection

In-Band SQL Injection is the most basic and common type of SQLi attack. It involves using the same communication channel for both launching the attack and retrieving the results. In-Band SQL Injection has two subtypes:

• Error-Based SQL Injection

Error-Based SQL Injection leverages database error messages to gather information about the structure of the database. Here’s how it works:

• Injection of Malicious Code: The attacker injects SQL code into an input field that causes an error in the SQL query.
• Retrieving Information from Error Messages: The database returns an error message that reveals details about the database schema, table names, column names, and other information. These details can be used by the attacker to craft further attacks.

Example: Suppose a website uses the following SQL query to fetch user details based on a username input:

SELECT * FROM users WHERE username = ‘user_input’;

If the attacker inputs ‘ OR 1=1–, the query becomes:

SELECT * FROM users WHERE username = ” OR 1=1–‘;

If there’s an error in the query, the database might return an error message revealing the table structure or other details.

• Union-Based SQL Injection.

Union-Based SQL Injection exploits the UNION SQL operator to combine the results of two or more SELECT statements into a single result. This allows the attacker to retrieve data from different tables within the database.

Example: Consider the same query as before. If the attacker inputs:

‘ UNION SELECT username, password FROM admin_users–

The query becomes:

SELECT * FROM users WHERE username = ” UNION SELECT username, password FROM admin_users–‘;

This causes the database to return the usernames and passwords from the admin_users table, exposing sensitive information.

2. Blind SQL Injection

When a web application doesn’t display any direct feedback such as database error messages, hackers use blind SQL injection technique. In this type of SQLi attack, the hacker sends payloads to the server and observes the responses (such as changes in page content, HTTP status codes, or time delays) to figure out whether the payloads executed successfully.

How to Detect WordPress SQL Injection Attacks

Detecting an SQL injection attack on your WordPress site can be challenging, but there are several signs and tools that can help you identify potential threats.

Signs of an SQL Injection Attack

1. Unexpected Contact Form Emails: An influx of unexpected emails via your site’s contact form can indicate an attack. These emails might be attempts to exploit vulnerabilities in your form inputs.
2. Strange Popups and Ads: If you notice unusual popups, ads, or error messages appearing on your site, especially if they redirect to suspicious websites, it could be a sign of an SQL injection.
3. Unexplained Database Changes: Unauthorized changes in your database, such as altered content or new administrative users, can also signal an SQL injection.

Unfortunately, not all SQL injection attacks are this obvious. Some hackers use these attacks to quietly steal information without leaving clear signs. This makes detection more difficult.

Detection and Scanning Tools for SQL Injection 

To accurately determine if your site has been targeted, you need to perform a scan using specialized tools. Several online tools can help detect SQL injection vulnerabilities on your WordPress site.

For instance, Pentest Tools offers a reliable solution for scanning your website. This tool provides two types of scans: a Light scan and a Full scan. The Light scan is available for free, while the Full scan requires a paid plan.

To use Pentest Tools, simply enter your website’s URL and click on the “Scan target” button. The scan will identify any present vulnerabilities.

Regular scans and monitoring are essential for maintaining the security of your WordPress site. By using these tools and keeping an eye out for suspicious activity, you can detect and address SQL injection attacks before they cause significant harm.

IMPORTANT: Before removing SQL injections from your site, make sure to lock down your website using the Password Protected plugin to prevent additional data breaches.

How to Remove SQL Injections From WordPress

Once you’ve detected the SQL injection attack on your WordPress site, it’s time to remove it. Removing SQL injections from your WordPress site can be daunting for most people, but you can do it with the right approach.

Here are a few effective ways to remove SQL injections and restore your WordPress site.

1. Restore Your Site’s Backup

The quickest way to remove SQL injections is to restore your site from a clean backup. If you use a reliable backup solution like Jetpack or Sucuri Backup, this process is very simple. Use the activity log to identify when the attack occurred, then restore a backup from before that point. This will revert your site to its state before the injection.

However, it’s important to note that SQL injections can occur gradually over time. In such cases, you might need to revert to an older backup to find a clean version, which could potentially lead to some data loss.

Also note that while restoring a backup can get your site up and running, it doesn’t automatically address any data breaches that may have occurred.

2. Use a Website Malware Removal Service

If you prefer a more hands-off approach, consider using a reputed website cleaning service. Services like Sucuri and Jetpack specialize in detecting and removing malware, including SQL injections.

Simply submit your website to their team, and they will handle the cleanup process. These experts can thoroughly scan and remove malicious code from your database, giving you a more comprehensive solution than you might achieve on your own.

3. Manually Remove the SQL Injection

For those with technical expertise, manually cleaning your database is an option. This approach requires a solid understanding of SQL and database management. You can start by identifying and isolating the malicious code. Then, carefully remove the injections from your database entries.

However, this method is not recommended for beginners, as improper handling can lead to further issues or even complete site failure. Always make sure you have a current backup before attempting any manual database modifications.

By following these steps and maintaining a proactive approach to security, you can effectively remove SQL injections from your WordPress site and protect it against future attacks.

How to Prevent Your WordPress Site From Future SQL Injection Attacks

Making any website 100% secure is impossible, but you can significantly reduce the risk by taking preventative measures. Here are some necessary precautions to prevent WordPress SQL injection attacks.

• Use Prepared Statements: Always use prepared statements and parameterized queries when interacting with the database. In this way, the server will treat user inputs as data and not executable code.
• Sanitize and Validate Inputs: Thoroughly sanitize and validate all user inputs. You must verify that all input commands are valid and do not contain any malicious code. 
• Regularly Update WordPress: Keep your WordPress core, themes, and plugins up to date. Updates often include security patches that fix known vulnerabilities.
• Install a Security Plugin: Use a reputable security plugin like Wordfence, Jetpack, or Sucuri. These plugins provide features like firewalls, malware scanning, and real-time threat detection.
• Limit User Privileges: Assign appropriate user roles and permissions. Only give database access to users who absolutely need it and restrict admin privileges.
• Use a Web Application Firewall (WAF): Implement a WAF to filter and monitor HTTP traffic between your website and the internet. This can block malicious SQL injection attempts before they reach your site.
• Regularly Backup Your Site: Maintain regular backups of your website. In case of an attack, you can restore your site to a previous clean state without losing too much data.
• Enable HTTP Security Headers: Configure HTTP security headers to protect against various types of attacks. This includes Content Security Policy (CSP) and X-Content-Type-Options.
• Monitor and Audit Your Site: Regularly monitor your site for suspicious activities and conduct security audits. Use tools and services that provide insights into potential vulnerabilities and unusual behavior.

If you follow these precautions, you can significantly reduce the risk of SQL injection attacks and enhance the overall security of your WordPress site.

Final Thoughts on WordPress SQL Injection Attacks

To protect your WordPress site from hackers, you need to understand common WordPress attacks, such as SQL injections. These attacks can expose sensitive data and cause significant financial damage.

As we’ve discussed, SQL injection attacks can have devastating effects on your WordPress site. However, there are several effective steps you can take to detect, remove, and prevent these attacks.

No website is ever completely safe, but by implementing the strategies outlined in this article, you can greatly reduce the risk of WordPress SQL injection attacks.

Lastly, in case of an SQL injection, lock down your website using the Password Protected plugin to prevent further data breaches.

Stay vigilant to maintain a secure and reliable website for your users.