ClickCease Code Execution Update: Improve WordPress Security

Content Table

Join Our Popular Newsletter

Join 4,500+ Linux & Open Source Professionals!

2x a month. No spam.

Code Execution Update: Improve WordPress Security

Wajahat Raja

December 18, 2023 - TuxCare expert team

In the ever-evolving landscape of digital security, WordPress has recently released a critical code execution update, version 6.4.2, addressing a potential threat that could jeopardize the integrity of vulnerable sites. This update, triggered by the discovery of a remote code execution vulnerability, brings not only bug fixes but also a crucial WordPress security patch aimed at fortifying your WordPress experience.


Unveiling the Vulnerability

The genesis of this
WordPress update news can be traced back to a well-intended feature introduced in WordPress 6.4. Designed to enhance HTML parsing in the block editor, this feature inadvertently opened the door to a vulnerability that could be exploited by threat actors.

Scope of Impact

It’s important to note that this vulnerability exclusively affects versions 6.4 and 6.4.1 of WordPress. Earlier versions remain unaffected, but if your site falls within this range, it is imperative to take swift action.

The Urgency of Code Execution Update

According to the
WordPress security advisory, WordPress 6.4.2, a minor yet pivotal release, not only brings seven bug fixes but also addresses the critical security flaw. The urgency to update is underscored by the recommendation from WordPress itself. As this is a WordPress vulnerability patch, prompt action is advised to fortify your site against potential threats.

Code Execution Update Process

Updating your WordPress site to the latest version is a straightforward process. You can download
version 6.4.2 directly from Alternatively, within your WordPress Dashboard, navigate to “Updates,” then click “Update Now.” For sites supporting automatic background updates, the critical security update for WordPress will commence automatically.

Behind the Flaw

Digging deeper into the technicalities, the vulnerability stems from the WP_HTML_Token class introduced in version 6.4. Meant to enhance HTML parsing in the block editor, this class inadvertently became the focal point of the identified flaw. WordPress security company Wordfence notes that while this vulnerability is not directly exploitable in the core, its severity escalates when combined with certain plugins, especially in multisite installations.

Potential Exploitation

Threat actors, armed with the ability to exploit a PHP object injection vulnerability present in other plugins or themes, can potentially chain the two issues. This could lead to the execution of arbitrary PHP code, granting unauthorized control over the targeted site.

Warnings from Security Experts

Security advisories from Wordfence and Patchstack highlight the gravity of the situation. A Property-Oriented Programming (POP) chain, if present via additional plugins or themes, could allow attackers to delete files, access sensitive data, or execute malicious code. As of November 17, an
exploitation chain is available on GitHub and has been incorporated into the PHP Generic Gadget Chains (PHPGGC) project, as reported by Patchstack.

Website Vulnerability Prevention

For developers, particularly those whose projects involve function calls to the unserialize function, caution is advised. Consider swapping this function with alternatives, such as JSON encoding/decoding using the json_encode and json_decode PHP functions. This proactive measure helps mitigate the risk associated with potential vulnerabilities.

Security Updates in Focus

WordPress 6.4.2 specifically addresses the identified
remote code execution fix. While not directly exploitable in the core, the security team emphasizes the potential for high severity when combined with certain plugins, particularly in multisite installations. This strategic focus on website security update reinforces WordPress’s commitment to creating a robust and safe digital environment for users worldwide.


In a digital landscape where threats are ever-evolving, WordPress remains vigilant in safeguarding its users. The swift response to the identified vulnerability through the release of the
cybersecurity patch for WordPress reflects a commitment to proactive security measures. As users, staying informed and promptly updating your WordPress site ensures a resilient defense against potential threats. Let us collectively contribute to a secure online ecosystem by embracing these WordPress security best practices and reinforcing the barriers against cyber threats.

The sources for this piece include articles in The Hacker News and WordPress.

Code Execution Update: Improve WordPress Security
Article Name
Code Execution Update: Improve WordPress Security
Stay secure with WordPress code execution update 6.4.2, shielding your site from code execution vulnerabilities.
Publisher Name
Publisher Logo

Looking to automate vulnerability patching without kernel reboots, system downtime, or scheduled maintenance windows?

Learn About Live Patching with TuxCare

Become a TuxCare Guest Writer

Get started




Linux & Open Source

Subscribe to
our newsletter