Vulnerability in acyba AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress

[ Description ]Official description

The AcyMailing plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the customField[] parameter of the public frontusers::subscribe endpoint in versions up to, and including, 11.1.0. This is due to insufficient input sanitization and output escaping in the acym_cleanVar() sanitizer, whose HTML-tag stripper only matches complete tags (requiring a closing '>'), together with SubscriberInsertion::replaceUserInformation() and the archive view template, which substitute the stored subscriber field value into the mail body and emit it without HTML encoding. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses the online-archive URL for the poisoned subscriber, including administrators who click the plugin-generated link in the Subscribers → History screen.

[ 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/acymailing/tags/11.1.0/back/Classes/FieldClass.php
• plugins.trac.wordpress.org/browser/acymailing/tags/11.1.0/back/Classes/UserClass.php
• plugins.trac.wordpress.org/browser/acymailing/tags/11.1.0/back/Core/wordpress/security.php
• plugins.trac.wordpress.org/browser/acymailing/tags/11.1.0/back/dynamics/subscriber/Subs…
• plugins.trac.wordpress.org/browser/acymailing/tags/11.1.0/front/FrontControllers/Frontu…
• plugins.trac.wordpress.org/browser/acymailing/tags/11.1.0/front/FrontViews/Archive/tmpl…
• plugins.trac.wordpress.org/changeset
• www.wordfence.com/threat-intel/vulnerabilities/id/eb8f03fb-d1af-4727-87d7-58dbe4013d8a