Securing WordPress: An In-Depth Guide To Core Vulnerabilities And Best Practices

Hardening WordPress Core Security

WordPress powers over 30% of all websites, making it an attractive target for hackers. While the WordPress core software is secure, vulnerabilities can be introduced through plugins, themes, and insecure configuration. Hardening the security of your WordPress site is crucial to prevent attacks like site takeovers, data theft, spamming, and more. This comprehensive guide covers actionable best practices for securing the WordPress core by identifying and mitigating vulnerabilities.

Identifying Common Vulnerabilities in WordPress

Being aware of the most common vulnerabilities that appear in WordPress allows you to better protect your site by proactively monitoring for and mitigating these security gaps. The top vulnerabilities include:

• Outdated plugins and themes – Unpatched older versions allow attackers to exploit known vulnerabilities. This enables them to inject malicious code onto your site. Always keep plugins and themes updated.
• Vulnerable database connections – Using default or weak MySQL settings makes your database prone to attacks like SQL injection which can lead to data theft. Secure your database credentials and connections.
• Weak user passwords – If an attacker gains access to an admin account by cracking or guessing passwords, they can gain full control over the site. Set strong passwords and enable two-factor authentication.
• Cross-site scripting (XSS) – Attackers can inject malicious JavaScript code into vulnerable templates and plugins which is then executed by visitors. Scan regularly for XSS issues.
• Incorrect file permissions – Overly broad write permissions allow attackers to modify .php files and inject backdoors. Lock down file permissions correctly.

Staying up to date on new threats and actively scanning for these common flaws is crucial for identifying and patching security gaps before they can be exploited.

Keeping Plugins and Themes Updated

One of the most important WordPress security best practices is keeping all your installed plugins and themes completely updated. When vulnerabilities are discovered, they are usually patched in the latest version so running outdated software makes you an easy target.

Log in to your WordPress dashboard and navigate to Plugins > Installed Plugins. Check the Version column for any plugins that are out of date and click Update Now. Be aware that some plugin developers are slower to release security patches so extra vigilance is required.

To keep plugins automatically updated, install a management plugin like Wordfence or iThemes Security which can update plugins hourly or daily in the background. You can also manually trigger bulk plugin updates from these plugins.

Take the same approach with themes by going to Appearance > Themes and checking for outdated software. Click update now to download the latest secure versions.

Be extremely cautious about installing random plugins and themes as these increase your attack surface. Only install reputable plugins with a large number of existing installs and always read reviews before installing a new plugin or theme.

Using Strong Passwords and Limiting Access

Having weak or default passwords for WordPress administrator accounts allows attackers to easily log in and control your site. Here are some tips for securing admin accounts:

• Enable two-factor authentication using a plugin to require a one-time code in addition to the password when logging in.
• Change the default “admin” username to make it harder to target that account.
• Use a randomly generated password that is over 12 characters, contains mixed case, numbers and special characters.
• Store the complex password securely in a password manager that syncs across devices.
• Limit admin access only to trusted site contributors and admins.
• Use the least privilege rule by only granting specific capabilities needed for each role.

Actively monitoring login attempts and failed logins through site analytics and monitoring plugins can alert you about brute force login attacks.

Configuring Secure Database Connections

Your WordPress site’s database contains sensitive information like username and passwords. Securing database connections prevent data theft through attacks like SQL injection. Follow these database hardening steps:

• Change the default database prefix to something random like a8x_ instead of the standard wp_.
• Use a strong password with uppercase, lowercase, numbers and symbols for your MySQL database user.
• Disable XML-RPC in WordPress which could allow brute force attacks. This is disabled by default since WordPress 5.5.
• Enable MySQL root login and restrict it only from the localhost to prevent remote database access.
• Disable external database connection protocols like FTP and enforce only secure connections.

Plugins like iThemes Security and Wordfence offer one-click access to many of these database hardening techniques for improved security.

Enabling Two-Factor Authentication

Two-factor authentication (2FA) acts as an extra layer of security by requiring you to enter a time-based one-time password (TOTP) code when logging into WordPress in addition to your normal login password. This means that even if your password is compromised, the attacker still cannot access your account without the TOTP code from your phone or authentication app.

Install and activate a dedicated two-factor authentication plugin like Google Authenticator, Authy or Duo Security. Then head to the plugin settings to configure 2FA for your account. You’ll be asked to scan a QR code using your phone’s authentication app like Authy or Google Authenticator. This links your account to the app to generate TOTP codes.

Once configured, each time you log into your WordPress account you’ll need to enter both your master password and the dynamically updating 6-digit TOTP code displayed on your phone. Enabling 2FA hardens your WordPress login security and significantly reduces the chances of account compromise through brute force or password guessing.

Monitoring for Malicious Activity

Carefully monitoring activity on your WordPress site allows quick detection and response to suspicious behavior indicative of hackers and malicious attacks. There are two main approaches to monitoring site activity:

1. Site analytics – Enable Google Analytics or Matomo to monitor detailed visitor trends, collect geographic data, analyze landing/exit pages, track download links and monitor engagement metrics. Unexpected drops in traffic or engagement can indicate issues. Frequently check your analytics dashboards.
2. Attack detection plugins – Install security monitoring plugins like Wordfence or iThemes Security which run frequent scans to detect changes to system files, malware infections, backdoors, Trojan code injections and other issues. They provide firewall protection, block bad IPs and enable attack notifications via email.

Monitoring WordPress activity at multiple levels provides visibility over attacks and helps quickly mitigate threats like hacker takeovers, spam injections, DDoS attacks and black hat SEO manipulation.

Performing Regular Backups and Updates

Having recent backups ensure that your WordPress site can be restored in the event of data corruption, accidental deletion or hackers wiping out content. Perform the following backup best practices:

• Backup your WordPress database and all site files daily using a dedicated backup plugin. ManageWP, UpdraftPlus and BackWPup are reliable options.
• Download backups to a local device or external cloud storage provider for enhanced redundancy in case of server disk failure.
• Test restoring from backups periodically to ensure that your site can effectively be recovered in the event of data loss.
• When updating themes, plugins or WordPress core itself, always backup immediately before and after changes to allow rolling back in case of issues.

Scheduling regular, redundant WordPress backups provides insurance against data loss and ensures uptime by allowing recovery with minimal disruption.

Following Secure Coding Practices

If your WordPress site allows user generated content like blog comments or uses custom themes/plugins, following secure coding guidelines protects against malicious input attacks like cross-site scripting and code injections:

• Escape all output – Encode special characters in output from custom modules using htmlspecialchars() to prevent XSS exploits inserted in comments, contact forms or other UGC.
• Input validation – Sanitize and validate ALL input variables and form fields submitted via plugins, themes and comments. Strip HTML tags, allow lists, length checks etc.
• Parameterized queries – Use prepared SQL statements via $wpdb parameterized queries instead of dynamic SQL which is prone to SQLi attacks allowing database compromise.
• Permissions checking – Check user permissions on all restricted actions using current_user_can().
• Nonce validation – Verify nonces on sensitive forms and actions to prevent CSRF attacks.

Following these coding best practices for all custom WordPress modules and addons drastically reduces the risk of common web exploits like XSS, SQLi, RFI etc.

Using a Web Application Firewall

A web application firewall (WAF) actively monitors all inbound traffic to identify and block SQL injections, cross-site scripting, hidden backdoors, malware uploads and other attacks. Install a dedicated WAF like Wordfence or Sucuri which offer the following protective capabilities:

• Blacklist known malicious IPs.
• Block exploitive HTTP requests methods.
• Filter traffic from untrusted geolocations.
• Prevent file upload attacks to introduce backdoors.
• Identify and block botnet traffic and DDoS attacks.
• Monitor all domains pointing to the server.
• Enable rate limiting to prevent brute force attacks.

Fine tuning WAF rules allows locking down external access while providing detailed visibility into all requests made to scan for threatening patterns proactively. Advance malware scans can detect backdoors and data exfiltration attempts missed by traditional anti-virus software.

Choosing a Reliable Web Host

The reliability and security of the underlying web host infrastructure impacts the attack surface of your WordPress site. When evaluating web hosting providers, consider these security criteria:

• Hardened Linux platforms like Ubuntu or CentOS with secure configurations.
• Strong DDoS mitigation and malware detection capabilities.
• SSH key-based login enforced for all accounts.
• Regular OS and software updates to address vulnerabilities.
• HTTP request flood prevention with rate limiting protection.
• IP whitelist capabilities to restrict access to known IPs.
• Geographic IP blocking to blacklist risky countries.
• SSD storage for faster recovery from backups.
• Granular firewall rules to tightly restrict traffic.

Choosing a managed WordPress host like WPEngine or Pagely provides additional security benefits including daily malware scans, automated patching, CDN protection, app armor capabilities and enhanced DDoS mitigation.

Ongoing Maintenance and Testing

Securing WordPress is not a one-time task. The ever-evolving threat landscape combined with a constant stream of new vulnerability disclosures makes ongoing maintenance essential. Build these tasks into your regular schedule:

• Daily plugin and theme updates to stay on top of patched vulnerabilities.
• Regular malware scans via anti-virus services to detect backdoors, trojans and data exfiltration attempts.
• Monitoring latest security advisories and making configuration changes as needed.
• Testing security measures like logins and backups to ensure protections remain working as expected.
• Reviewing permissions, credentials, database connections, file directories etc. every few months for unexpected changes.
• Testing new security approaches in staging environments before deploying to production.
• Budgeting for professional penetration testing every quarter to identify hardened weaknesses.

Proactively maintaining your WordPress site allows you to harden security, monitor threats, validate defenses and address vulnerabilities before they can be exploited by attackers.

Implementing all of these WordPress hardening techniques does require some effort but pays off tremendously in securing your site from compromise. Many items like plugin updates, malware scans and backups can be easily automated as well. With cyberattacks aimed at WordPress sites continuing to rise, taking a proactive approach to lock down the security of your site has become a mandatory business requirement.