In particular, users with the “edit_posts” or “edit_custom_post_types” capability can exploit this vulnerability to inject malicious code into posts or custom post types. Fortunately, the majority of WordPress installations will not have this capability, so this issue does not pose a risk to most WordPress users. However, if you do have the ability to create posts or custom post types, you should strongly consider blocking unfiltered_html from non-whitelisted origins to prevent this issue from being exploited.
WordPress versions other than 3.0 are not affected by this issue.
What to do about it: Upgrade to version 3.37.2 or 3.38.1 as soon as possible. If you cannot upgrade, you should block unfiltered_html from non-whitelisted origins to prevent this issue from being exploited.
How to check if you are vulnerable
The easiest way to check if your WordPress installation is vulnerable is to test it with a specially crafted URL.
To generate this URL, add the following to your theme's functions.php file:
add_filter( 'preprocess_html', '__filter_preprocess_html' );
function __filter_preprocess_html($content) {
$content = preg_replace('/(
Wordpress version 3.0 – unfiltered_html vulnerability
WordPress is an open-source content management system (CMS), and as such, it has many vulnerabilities. In particular, users with the “edit_posts” or “edit_custom_post_types” capability can exploit this vulnerability to inject malicious code into posts or custom post types. Fortunately, the majority of WordPress installations will not have this capability, so this issue does not pose a risk to most WordPress users. However, if you do have the ability to create posts or custom post types, you should strongly consider blocking unfiltered_html from non-whitelisted origins to prevent this issue from being exploited.
Wordpress versions other than 3.0 are not affected by this issue.
What to do about it: Upgrade to version 3.37.2 or 3.38.1 as soon as possible. If you cannot upgrade, you should block unfiltered_html from non-whitelisted origins to prevent this issue from being exploited.
The unfiltered HTML filter is Broken
WordPress versions other than 3.0 are not affected by this issue.
What to do about it: Upgrade to version 3.37.2 or 3.38.1 as soon as possible. If you cannot upgrade, you should block unfiltered_html from non-whitelisted origins to prevent this issue from being exploited.
What is unfiltered_html?
Unfiltered_html is a function in WordPress 3.0 that allows users to visit any website in order to view the HTML source. This function can be used intentionally or unintentionally.
Timeline
Published on: 09/26/2022 13:15:00 UTC
Last modified on: 09/27/2022 03:43:00 UTC