django CMS: Structure endpoint bypasses page-view permission

Summary

The structure-board endpoint (render_object_structure) renders a page's plugin structure without verifying that the requesting user is allowed to view the page. The edit and preview endpoints enforce this via render_page(), but the structure endpoint does not, allowing a low-privileged staff user to read the plugin structure of a view-restricted page.

Details

render_object_structure (in cms/views.py) loads the PageContent object and renders cms/toolbar/structure.html directly. Unlike render_object_endpoint (used by edit/preview), which renders through render_pagecontent → render_page and calls user_can_view_page(request.user, page) (returning 404 when the user may not view the page), the structure endpoint performs no page-level authorization.

The rendered structure board includes each plugin's get_short_description() (e.g. link names/URLs, text snippets), so the content of a restricted page is disclosed, not just its shape.

Impact

A staff user (any account with is_staff=True) who lacks view permission on a view-restricted page can retrieve that page's plugin structure and short descriptions by requesting the structure endpoint with the page's content-type id and object id.

This only applies when CMS_PERMISSION=True and the page has view restrictions (or CMS_PUBLIC_FOR='staff'). Sites without per-page view restrictions are not affected.

Patches

Fixed in 5.0.8: the structure endpoint now enforces user_can_view_page() for PageContent objects, matching edit/preview.

Workarounds

None other than restricting staff access. Upgrade is recommended.

Credits

Reported by the security team at the University of Sydney ([@reporter]).