One of the reasons WordPress is among the most popular platforms—and why I use it—is its diverse library of plugins and themes. With themes, you can customize your website’s appearance, and plugins allow you to add extra functionality. However, if you’re not careful with how you use them, your website’s security could be compromised, potentially leading to data breaches and hacks.
A 2021 study shows that themes account for 6.61% of all vulnerabilities, while plugins are responsible for 92.81%. This makes it crucial for WordPress website owners and admins to be extra cautious when using plugins and themes.
Today, I’ll Walk you through how hackers exploit these vulnerabilities to compromise websites and what you can do to avoid becoming the next victim.
Why Plugins and Themes Are a Security Risk
The Role of Plugins and Themes in WordPress Functionality
Plugins and themes are essential to WordPress because they allow users to customize their websites. For instance, plugins add features like contact forms, SEO tools, and security enhancements, while themes control the site’s design and layout.
That is why it is almost impossible to run a WordPress website without installing a third-party theme and plugins. However, because they involve third-party code, they can introduce security vulnerabilities if not properly managed.
Outdated or Poorly Coded Plugins and Themes
Many vulnerabilities come from outdated or poorly developed plugins and themes. Most theme and plugin developers regularly release updates to fix security flaws, but if users don’t update them, hackers can exploit known weaknesses.
When developers fix a security issue, they typically mention it in the update notes. With this information availed publicly, hackers can now target websites that haven’t updated their software promptly.
Poorly coded plugins and themes may also have security gaps that allow attackers to inject malicious code or gain unauthorized access to your site. This is common with newer developers who might not be well versed with the security best practices for coding themes and plugins. Installing such plugins and themes will put your website at risk.
Nulled (Pirated) Themes and Plugins
Nulled themes and plugins are pirated versions of premium versions of these products. They often contain hidden malware or backdoors, allowing hackers to access websites without the owner’s knowledge.
Many website owners feel tempted to use these nulled plugins because they are often available for free and provide access to all features that legitimate developers might charge for. Since these versions don’t receive official updates, they become even more vulnerable over time.
Using nulled software poses serious security risks, including data theft or even taking over the website if they realize it has value.
Common Ways Hackers Exploit Plugins and Themes
Let’s explore some of these four common methods attackers use to exploit vulnerabilities in plugins:
1. Backdoor Infections
Backdoor infections occur when hackers insert hidden scripts into a website, usually by exploiting vulnerabilities in themes, plugins, or even core WordPress files. These scripts act as secret entry points that allow attackers to regain access to the site at any time, even if the website owner removes the infected plugin or changes login credentials.
Backdoors are commonly found in nulled (pirated) themes and plugins, as these often come pre-loaded with malicious code. Attackers can then use the backdoors to:
- Upload more malware
- Create new admin accounts
- Steal data or inject spam content
- Use the website for phishing or distributing malware
2. SQL Injection (SQLi)
SQL injection happens when a website fails to sanitize and validate user input, allowing attackers to manipulate database queries. This vulnerability often appears in poorly coded plugins or themes that accept user input through contact forms, search boxes, login pages, and more.
Attackers can exploit SQLi to steal sensitive user information, modify or delete website data, or even gain full admin access, enabling them to take over the website.
3. Cross-Site Scripting (XSS)
XSS attacks involve injecting malicious JavaScript code into a website, typically through vulnerable plugins, themes, or comment sections. Unlike SQL injection, which targets databases, XSS focuses on users and their browsers.
When a victim visits an infected page, the malicious script runs in their browser. This can lead to:
- Session hijacking – Attackers steal login cookies and impersonate users
- Phishing and redirects – Users are tricked and redirected into visiting fake websites where they are prompted to share sensitive information, such as credit card details.
- Defacement – Hackers modify webpage content with unwanted messages
- Malware distribution – Users unknowingly download malicious files
4. Remote Code Execution (RCE)
Remote Code Execution is one of the most dangerous WordPress security vulnerabilities. It allows attackers to execute arbitrary code on the website’s server, gaining full control. This usually happens due to unpatched vulnerabilities in themes or plugins, misconfigured file permissions, and weak security settings.
With RCE access, hackers can:
- Upload malware, backdoors, or ransomware
- Modify, delete, or steal website files
- Create admin accounts for persistent access
- Use the website for further attacks, such as cryptojacking or DDoS botnets
How to Protect Your WordPress Site
To minimize or even eliminate the risk of attackers exploiting your site through installed plugins and themes, follow these simple best practices:
- Only Use Trusted Plugins and Themes: Always download plugins and themes from reputable sources like WordPress.org, ThemeForest, or directly from trusted developers’ websites. Avoid nulled (pirated) versions, as they often contain malware.
- Keep Everything Updated: Hackers often exploit outdated WordPress core files, plugins, and themes. Regularly update them to ensure security patches are applied and vulnerabilities are fixed. You can enable auto-updates for all the plugins and themes that support this feature.
- Remove Unused or Abandoned Plugins: If a plugin is no longer maintained by its developer or you don’t use it, remove it from your site. Old, unsupported plugins can become security risks over time.
- Scan for Malware Regularly: Use security plugins like Wordfence or Sucuri to scan your website for malware, suspicious changes, and vulnerabilities. These tools can also help detect and block hacking attempts.
Key Takeaway
Attacks made through plugins are quite common and can potentially lead to major threats that could cause you to lose access to your site or infect it with harmful malware. Since we cannot avoid using plugins and themes on our sites, the only option is to use them while following best practices.
These practices are fairly simple and cost nothing – only install software from legitimate sources, keep it updated, uninstall abandoned themes/plugins, and conduct regular malware scans to detect infections before they become problematic.