SQL Injection (SQLi) in WordPress: What It Is and How to Prevent It

What is SQL Injection (SQLi)?

SQLi is a vulnerability where an attacker can manipulate an input field or URL on a website to inject malicious SQL commands directly into the WordPress database. If successful, these commands can expose user data, modify content, or even create a new administrator account.

It’s commonly found in poorly coded plugins, themes, or custom scripts that don’t properly validate user input.

How to Prevent it?

Keep WordPress, Themes and Plugins Updated

This seems like a simple way of preventing it, but it’s also the most effective. Popular themes and plugins have teams of developers who are consistently improving their own code and staying ahead of security trends to prevent these kinds of attacks.

The most common method of SQL injection is through out-of-date or vulnerable code. This code might have already been fixed in a recent update, but if you don’t update the plugin on your site… you remain vulnerable.

Use a Web Application Firewall (WAF)

Security plugins like Wordfence or services like Cloudflare WAF can actively block malicious SQL payloads before they reach your site. They detect common SQLi patterns or union-based injection attempts.

Restrict Direct Database Access (Where Possible)

Avoiding or limiting direct access to the database via plugins or custom APIs is another way of limiting any vulnerability to SQLi attacks. This can be done by restricting access to /wp-admin pages, or XML-RPC and other custom endpoints. My managed hosting takes care of this at the server level.