hi Jean-Pierre,
thank you very much for the fast reply. 
i am not at home until beginning of next week, so i can sadly not provide you with some detailled photography.
anyhow, i tried to create a small diagram that should represent my current situation.
i want to send fastboot commands to dut and while the dut is executing these commands do some glitching. then finally i want observe if there is some “interesting” behaviour observable.
i have currently no idea, how i could connect my dut to the cw308 so that the dut receives commands on its usb interface and responds to these again on the usb interface. (like in the attached diagram)
i have read in some other post that you need some additional hardware (like greatFET) to realize this in general.
i found this just after creating my post. 
but yeah anyhow, maybe someone can think of an other scenario, in which i d not necessarily have to buy new hardware again.
the phywhisperer-usb looks pretty cool! this should make things way easier…
definitely will have a closer look when someday in near future i am not a poor student anymore
have a great weekend guys!