XenForo before 2.2.14 allows Directory Traversal (with write access) by an authenticated user who has permissions to administer styles, and uses a ZIP archive for Styles Import.
https://xenforo.com/tickets/BC37EB98/?v=5da7bd5728
https://xenforo.com/docs/xf2/permissions/
https://xenforo.com/community/threads/xenforo-2-2-14-released.219044/