The bug in iOS 11.03 allows you to bypass iCloud completely, but only for devices in Clean mode. This bug happens on iCloud lock activation screen, before you activate your device. And one more, it works only on linked accounts, where 2-factor authorization is enabled.
Since Apple recently replaces all of them with 2-factor authorisation, it can be considered that it will work on most devices.
Restore your device’s firmware to iOS 11.0x.
Select “touch unlocked by a passcode” option.
Enter any digits two times.
Tap on “Back” twice.
Tap on “Next” button.