WordPress 5.1.1 Fixes Vulnerability That Leads to Website Takeovers
The Cybersecurity and Infrastructure Security Agency (CISA) issues a notice on US-CERT that any website using WordPress version 5.1 or earlier are affected by a vulnerability. A hacker could exploit the vulnerability in the default user comments module and use it to take control of the website. WordPress Related Vulnerabilities increased 30% Uptick in 2018.
US-CERT is part of the Department of Homeland Security.
This security update includes two patches that change how comments are filtered and then stored in the database. With a maliciously crafted comment from a hacker, a WordPress post was open to cross-website scripting (coding.) WordPress versions 5.1 and earlier are affected by this issue.
In response to the warning, WordPress released version 5.1.1 as a short-cycle maintenance release to patch the vulnerability. CISA advises WordPress administrators and website owners to upgrade to the newest version, WordPress 5.1.1, immediately to avoid being compromised.
WordPress is popular and is used as a content management system for over 33% of all websites in the world. Comments are a core feature of blogs and are enabled by default. Gary Pendergast, also a WordPress core developer, suggested a work-around for websites that are not yet ready to upgrade to the latest WordPress release. Sites that have WordPress themes that use wp_print_scripts() can turn off comment threading is turned off. Admins should also log out before visiting any other website.
The vulnerability allows hackers to perform stored cross-site scripting (CSS) attacks using maliciously crafted comments. The attacked WordPress website must have user comments enabled. The vulnerability makes it possible for hackers to take over the WordPress site using a cross-site request forgery vulnerability. An administrator level user of the attacked site is tricked into visiting a malicious website containing a CSS executable file. The administrator does not notice anything on the spoof website and does interact in any way.
The XSS payload is executed with the help of a hidden iFrame, allowing hackers to execute HTML and script fully taking over the unpatched WordPress website.
A WordPress 5.1.1 download is available now if your site has not automatically updated itself. Check for an update on your WordPress site, visit Dashboard → Updates and click Update Now.