14 WordPress Security Issues & Vulnerabilities You Should Know About [New Research from WCEU 2022]

WordPress powers over 43% of all websites on the internet, making it not just the most popular content management system (CMS) but also a major target for hackers and cybercriminals. Website security firm Wordfence reported over 4.3 billion attempted attacks on WordPress sites in 2020 alone.

As a WordPress site owner, it‘s critical to understand the potential security vulnerabilities that can put your website, data and visitors at risk. While the core WordPress software emphasizes security, issues more commonly arise from its extensible components like plugins and themes, as well as configuration settings. Here‘s an in-depth look at the top WordPress security issues you need to defend against in 2024 and beyond.

1. Outdated Core Software, Themes & Plugins
One of the leading causes of WordPress site compromises is running outdated versions of the core WordPress software, themes or plugins. These components are updated frequently by their developers to add new features, fix bugs and patch security holes. If you fail to promptly install the latest versions, your site can be vulnerable to known exploits.

According to WordPress security company Sucuri, 49% of hacked WordPress sites in 2021 were running outdated core software at the time of infection. 52% had an outdated plugin installed. Alarmingly, some vulnerabilities have been found in plugins with over 1 million active installations. To mitigate risks:

  • Enable auto-updates for WordPress core
  • Remove unused themes and plugins
  • Configure alerts for theme/plugin updates
  • Update all components at least monthly if not using auto-updates

2. Brute Force Attacks & Unauthorized Logins
Brute force attacks attempt to gain unauthorized access to your WordPress admin area by rapidly guessing username/password combinations, often using common/weak credentials. Once inside, a hacker could deface your site, steal data, install malware, create new admin accounts and cause havoc.

To protect your login page from brute force attacks:

  • Use strong passwords over 10 characters with upper/lowercase letters, numbers and symbols
  • Enable two-factor authentication (2FA)
  • Limit failed login attempts with a plugin or server-side tool
  • Change the default "admin" username
  • Consider changing the wp-admin URL

3. Undefined User Roles & Permissions
WordPress offers six user roles with predefined capabilities – Administrator, Editor, Author, Contributor and Subscriber. The default role of Administrator has the most control over your site.

Where many WordPress site owners get into trouble is assigning Administrator access too liberally. Whether it‘s to employees or freelancers working on your site, or just not changing the default on new accounts, having multiple users with more access permissions than they require widens your attack surface. If any of those accounts gets compromised, the attacker gains full control.

Restrict Administrator access to only those who absolutely need it. For other user levels, follow the principle of least privilege – only grant the minimum permissions required for their responsibilities. Also consider:

  • Implementing a custom user role plugin for more granular access control
  • Periodically auditing user accounts and permissions
  • Removing inactive users and old accounts

4. SQL Injection Attacks
SQL (Structured Query Language) is used to interact with the databases that power WordPress sites. SQL injection attacks attempt to manipulate database queries by inserting malicious code, often through user input fields like login forms, search bars or contact forms.

A successful SQL injection can allow the attacker to access, modify or delete sensitive information in your WordPress database – everything from user credentials to payment data to posts and pages. They may even be able to take over your site entirely.

To protect against SQL injection vulnerabilities:

  • Update WordPress core, plugins and themes to get the latest security patches
  • Validate and sanitize user input submitted through forms
  • Use parameterized queries or prepared statements instead of dynamically generated SQL
  • Implement a web application firewall (WAF) that looks for SQLi attempts
  • Harden your wp-config.php file and database

5. Cross-Site Scripting (XSS) Attacks
Cross-site scripting vulnerabilities allow an attacker to inject client-side scripts into web pages viewed by other users. Typically, the malicious JavaScript is inserted into content via user input fields and executed in the victim‘s web browser.

The impact can range from defacing your site to redirecting visitors to a malware-laden page to hijacking user sessions to steal personal data. Stored XSS attacks, where the script is saved in your database and keeps affecting users, can be particularly devastating.

XSS vulnerabilities have plagued even the WordPress core as recently as 2022. To defend your site:

  • Keep WordPress core and extensions updated
  • Escape user input when outputting it
  • Validate and sanitize user input submitted through forms
  • Use security plugins that protect against XSS
  • Implement Content Security Policy (CSP) headers to restrict executable scripts

6. Malware & SEO Spam
Hackers can inject malicious code into the files of vulnerable WordPress sites to serve up spam content, redirect visitors to sketchy websites, steal sensitive data, or co-opt your server resources for DDoS attacks and cryptocurrency mining.

Malware can infiltrate via trojans in nulled (pirated) themes and plugins, code/SQL injection, or access gained through compromised credentials. Sneaky SEO spam that inserts spammy keywords and links into your top-performing pages to boost a bad actor‘s search rankings has also surged.

Defend your site with:

  • Regular automated malware scans
  • Manual checks of recently modified files/databases
  • Post-hack security hardening
  • Removal of unused themes/plugins
  • Web application firewalls

7. Denial-of-Service (DoS) Attacks
In a Denial-of-Service attack, a hacker attempts to take down your website and make it inaccessible to visitors by overwhelming the server with a flood of traffic, usually leveraging a botnet of hacked devices for a Distributed Denial-of-Service (DDoS). Even a brief outage resulting from a successful DDoS attack can inflict massive damage in terms of lost sales, ad revenue and brand reputation.

While not specific to WordPress, any WordPress hosting environment can be targeted. To protect your site:

  • Use a hosting provider or CDN with DDoS protection
  • Harden your WordPress security to prevent hackers from planting DDoS attack tools on your server
  • Implement rate limiting and IP blocking tools
  • Maintain an incident response plan

8. Phishing & Social Engineering Attacks
Not all WordPress security breaches are technical – some exploit the human factor. In phishing attacks, hackers impersonate your brand to trick users into revealing login credentials or financial information. Targeted spear phishing aimed at your employees or contributors could give cybercriminals backdoor access to your site.

Educating your team on phishing identification and implementing email security best practices (like SPF and DMARC) are key to avoiding compromise. Also lock down your WordPress site with:

  • 2FA on all accounts
  • Strong password policies
  • Principle of least privilege for user roles
  • Alerts for suspicious admin activity

9. Supply Chain Attacks & Malicious Plugins/Themes
The massive plugin and theme ecosystem is part of what makes WordPress so powerful – but it‘s also a massive attack vector. Nulled (pirated) plugins and themes are often trojans containing backdoors. Developers of free plugins may abandon them, letting vulnerabilities go unpatched. Attackers may even buy formerly legitimate plugins or hijack developer accounts to distribute malware to thousands of sites.

Only install plugins and themes from reputable sources, and keep them updated. Vet the developers, check reviews and support forums, and steer clear of plugins that haven‘t been updated in over a year. Use a plugin security scanner to identify vulnerabilities and consider a tool like BlogVault‘s Website Integrity Monitor to get alerted of unexpected file changes.

10. Insecure Hosting & Misconfigurations
Your WordPress site security is only as strong as its weakest link – and often, that‘s the server it‘s hosted on. No amount of security plugins can protect you if your hosting company doesn‘t properly secure its platform. Shared hosting environments are especially risky, as a breach of another site on the same server could lead to yours getting hacked too.

Choose a reputable managed WordPress host that takes a security-first approach, with safeguards like:

  • Isolated environments for each site
  • Web application firewalls and DDoS protection
  • Malware scanning and cleanup
  • Robust access control and account security
  • Intrusion detection and incident response

Also be sure to properly configure your WordPress settings, like changing the default table prefix, restricting file permissions, disabling XML-RPC and REST API if not used, and enforcing HTTPS/SSL. A single misconfiguration could open the door to attackers.

The Bottom Line
WordPress security is a never-ending battle against constantly evolving threats. While no site is 100% impenetrable, taking a proactive, layered approach to security can greatly reduce your risk of falling victim to an attack.

The most effective WordPress security strategy includes:

  1. Keeping WordPress core, plugins and themes updated
  2. Choosing high-quality plugins/themes and removing unused ones
  3. Implementing strong access controls and user permissions
  4. Enabling 2FA and enforcing strong password policies
  5. Using a security plugin for firewall, malware scanning and hardening
  6. Hosting with a secure managed WordPress provider
  7. Regularly backing up your entire WordPress site
  8. Continuously monitoring for signs of compromise
  9. Having an incident response plan to quickly contain breaches

Don‘t wait until your WordPress site gets hacked to start thinking about security. By proactively implementing these WordPress security best practices and staying vigilant, you can protect your site, your users and your business from costly attacks.