Samsung Galaxy devices running proprietary Android versions come with a back-door that provides remote access to the data stored on the device. Back-door is present in most proprietary Android systems running on the affected Samsung devices, including the ones that are shipped with the devices. When Replicant is installed on the Samsung Galaxy device, the device does not cooperate with back-doors. The Free Software Foundation has published a statement on the issue. The software implementation appends /efs/root/ to the provided path but it’s fairly simple to escape that path and request any file on the file system.”]
Source: https://redmine.replicant.us/projects/replicant/wiki/SamsungGalaxyBackdoor