Kirki <= 6.0.13 - Authenticated (Editor+) Path Traversal to Arbitrary File Write (Zip Slip)

The Kirki – Freeform Page Builder, Website Builder & Customizer plugin for WordPress is vulnerable to Path Traversal (Zip Slip) in all versions up to, and including, 6.0.13 via the extract_zip_file function. This makes it possible for authenticated attackers, with custom-level access and above, to write arbitrary files on the server, which can allow for remote code execution. The install_app, update_app, and get_kirki_template_from_zip code paths accept a user-supplied app src value to construct the download URL, and no sanitization is applied to prevent a crafted ZIP from being fetched and extracted with path-traversing entry names that escape the intended destination directory.