There seems to be serious flaws in operating systems security including Linux that can happen whenever connecting to any network (pstn/wlan/umts04g/etc).
I had to travel to another country and I'm currently ruling out whethersoftware or hardware or both have backdoors(?) and trying to move to a custom kernel (the good old 2.x days when things were simple) and hardware (FPGA boards).
For example, iphone se wifi tethering worked before but not anymore and they apprarently managed to use USB (CONFIG_USB_IPHETH) to gain control one of my computer systems (Acer Aspire V3-371 3.16.7-ckt20-1+deb8u3 x86_64)until my iphone didn't share connection at all. Currently, ipheth.c returns TX errors before calling ipheth_tx() and starts trying to send a 0x33330 packet.
Android 5.1, Linux (Kali,Debian 5-8,Tails,Slackware etc), Win10, iOS 9.3.2 all seem to be affected when used.
Do you know status of russian, chinese, iranian, venezuelan etc. operating systems like Canaima and their CPUs? What about (closed) modern operatingsystems?