The Click to Chat for WhatsApp plugin for WordPress is vulnerable to Arbitrary Shortcode Execution…

Why it is Amber

• CVSS 9.1 critical
• Remotely exploitable without logging in

References

• https://plugins.trac.wordpress.org/browser/click-to-chat-for-whatsapp/tags/4.44/new/inc/greetings/class-ht-ctc-chat-greetings.php#L111
• https://plugins.trac.wordpress.org/browser/click-to-chat-for-whatsapp/tags/4.44/new/inc/greetings/class-ht-ctc-chat-greetings.php#L224
• https://plugins.trac.wordpress.org/browser/click-to-chat-for-whatsapp/tags/4.44/new/inc/greetings/greetings-1.php#L22
• https://plugins.trac.wordpress.org/browser/click-to-chat-for-whatsapp/tags/4.44/new/inc/greetings/greetings-2.php#L18
• https://plugins.trac.wordpress.org/changeset/3716433/click-to-chat-for-whatsapp/trunk/new/inc/greetings/greetings-1.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/cf625e34-1f51-42a3-8daa-a5188dea226e?source=cve

Original description

The Click to Chat for WhatsApp plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions up to, and including, 4.44 This is due to the greetings_dialog() function building the {url} template placeholder from a sanitize_text_field()-filtered $_SERVER['REQUEST_URI'] on archive pages and then passing the substituted greeting content to do_shortcode() in the greetings-1 and greetings-2 templates, without stripping shortcode delimiters. Because wp_kses() runs against main_content BEFORE the {url} substitution, the attacker-controlled URL bytes reach do_shortcode() unfiltered. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes registered by WordPress core, the active theme, or any other plugin (e.