Many IoT devices have a UART connector somewhere on the board. It is often used to debug the device before mass production. Sometimes there will be a nice four pin header to connect to. Other devices give you just some plated through holes ready to solder. In some cases the holes exist but the traces have been disconnected in the final layout. In any case if you can connect to it you can often obtain device logs, issue commands and sometimes access the boot loader. If you’re lucky you can get full shell access over UART.
In the first part of a teardown of a D-Link DCS-932L internet enabled security camera, I looked at extracting firmware from flash memory. In this second part, I look at connecting to UART and using the root shell to have a rummage about the camera’s file system.