Due to a type confusion during initializations, the tun and tap sockets in the Linux Kernel have their socket UID hardcoded to 0, i.e. root. While it will be often correct, as TUN/TAP devices require CAP_NET_ADMIN, it may not always be the case. The socket UID may be used for network filtering and routing, thus TUN/TAP sockets may be incorrectly managed, potentially bypassing network filters based on UID.