I'm running raspbian stertch and need to create a guest user to use the raspberry pi with limited permissions. To be specific, I'd like to prevent the guest user from using Bluetooth and wifi.
I found some posts here about dtoverlay method. But can the guest user change the /boot/config.txt
This is normally controlled by adding/removing users from different groups.
So remove the guest user from the netdev group.
Ref.: https://wiki.ubuntu.com/Security/Privileges#Connect_to_wireless_and_ethernet_networks
On Debian, the "netdev" group gains access to using Network Manager. On Ubuntu, Network Manager access rights are gained by being at the system console, so the name of this entry in gnome-system-tools is misleading.
The "netdev" group can administer wicd and wpasupplicant.
The "netdev" group can set the avahi host name using DBus.
The "netdev" group can administer Bluetooth devices.
sudo. You should update your answer.