Vulnerability in stepasyuk Filter Everything — WordPress & WooCommerce Filters

[ Description ]Official description

The Filter Everything — WordPress & WooCommerce Filters plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 1.9.6. This is due to insufficient input sanitization and output escaping in the flrt_elementor_load_more_anchor() function. The function reads query parameters from $_SERVER['REQUEST_URI'] via getFormActionOrFullPageUrl(true), which URL-decodes them through parse_str() and re-assembles them using build_query() — a WordPress core function that does NOT re-encode values ($urlencode=false). The resulting URL, containing unescaped special characters, is injected into a data-next-page HTML attribute via preg_replace() without esc_attr() or esc_url(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.2.1/src/UrlManager.php
• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.2.1/src/wpc-helpers.php
• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.2.1/src/wpc-third-party.php
• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.6/src/UrlManager.php
• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.6/src/wpc-helpers.php
• plugins.trac.wordpress.org/browser/filter-everything/tags/1.9.6/src/wpc-third-party.php
• plugins.trac.wordpress.org/changeset
• www.wordfence.com/threat-intel/vulnerabilities/id/7f0f453c-ca01-4ccc-b8c0-4468db40386a