The Starter Templates by Kadence WP WordPress plugin before 1.2.17 unserialises the content of an imported file, which could lead to PHP object injection issues when an admin import (intentionally or not) a malicious file and a suitable gadget chain is present on the blog.

On sites that also had the Elementor plugin for WordPress installed, it was possible for users with the editposts capability, which includes Contributor-level users, to import blocks onto any page using the astra-page-elementor-batch-process AJAX action. An attacker could craft and host a block containing malicious JavaScript on a server they controlled, and then use it to overwrite any post or page by sending an AJAX request with the action set to astra-page-elementor-batch-process and the url parameter pointed to their remotely-hosted malicious block, as well as an id parameter containing the post or page to overwrite. Any post or page that had been built with Elementor, including published pages, could be overwritten by the imported block, and the malicious JavaScript in the imported block would then be executed in the browser of any visitors to that page.