Description

The Elementor Website Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the _elementor_data meta field in versions up to, and including, 4.0.4. This is due to insufficient input sanitization when processing form-encoded REST API requests. The plugin registers the _elementor_data meta field with show_in_rest but omits a sanitize_callback, relying instead on a rest_pre_insert_post filter (sanitize_post_data function) that only sanitizes JSON-encoded request bodies. When a contributor sends a form-encoded PATCH request to the WordPress REST API, the json_decode() call on the raw body returns null, causing all sanitization to be skipped. The unsanitized data is then stored via update_post_meta() and later output without escaping through multiple widget sinks including the HTML widget's print_unescaped_setting() function. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Weaknesses 1

References 8

• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/tags/4.0.1/includes/base/widget-base.php#L794
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/tags/4.0.1/includes/plugin.php#L840
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/tags/4.0.1/modules/wp-rest/classes/elementor-post-meta.php#L68
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/trunk/includes/base/widget-base.php#L794
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/trunk/includes/plugin.php#L840
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/elementor/trunk/modules/wp-rest/classes/elementor-post-meta.php#L68
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/changeset/3519457/
• wordfence.com https://www.wordfence.com/threat-intel/vulnerabilities/id/826a2003-c526-4760-8c21-10d5ae7bb384?source=cve

Remediation