CVE-2026-17577
Description
The SSL Zen plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'uri' (and 'host') parameters in versions up to, and including, 4.7.42. The ssl_zen_messages::getMessages() function builds the 'token_missmatch' message using base64_decode(sanitize_text_field($_REQUEST['uri'])) and (optionally) base64_decode(sanitize_text_field($_REQUEST['host'])). sanitize_text_field() cannot strip HTML/JavaScript that is hidden inside a base64-encoded blob, and the resulting decoded raw HTML is echoed unescaped by showMessage() . 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.
References
- https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_admin.php#L863
- https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_messages.php#L44
- https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_admin.php#L863
- https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_messages.php#L44
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3701590%40ssl-zen&new=3701590%40ssl-zen