WiX toolset lets developers create installers for Windows Installer, the Windows installation engine. The custom action behind WiX's `RemoveFolderEx` functionality could allow a standard user to delete protected directories. `RemoveFolderEx` deletes an entire directory tree during installation or uninstallation. It does so by recursing every subdirectory starting at a specified directory and adding each subdirectory to the list of directories Windows Installer should delete. If the setup author instructed `RemoveFolderEx` to delete a per-user folder from a per-machine installer, an attacker could create a directory junction in that per-user folder pointing to a per-machine, protected directory. Windows Installer, when executing the per-machine installer after approval by an administrator, would delete the target of the directory junction. This vulnerability is fixed in 3.14.1 and 4.0.5.

Malicious directory junction can cause WiX RemoveFoldersEx to possibly delete elevated files

Уязвимость функции RemoveFolderEx набора инструментов создания установочных пакетов WiX Toolset операционной системы Windows, позволяющая нарушителю удалить произвольные файлы