Vulnerability in sslzen SSL Zen — SSL Certificate Installer & HTTPS Redirects

[ Description ]Official 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.

[ 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/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_ad…
• plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_me…
• plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_ad…
• plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_me…
• plugins.trac.wordpress.org/changeset
• www.wordfence.com/threat-intel/vulnerabilities/id/20816039-0b1c-420a-b5f4-b5370d0331da