My Macbook pro got disabled. I tried to go into the recovery mode using cmd+R and internet recovery mode using cmd+opt+R. Both ask for my firmware password, and when I enter the password,although correct, it takes me back to disabled screen. Find my Iphone app says my Macbook is locked.In addition I tried to reinstall OS through bootable installer but that too takes me back to the disabled screen.
If you are indeed locked out due to the FirmwarePasswordUtility preventing you from Internet Recovery mode, and cannot manage figuring out what your password is, there is still a last resort option.
Assuming you do actually own, and can prove you own the Mac, an official Apple Store can remove the firmware password and help you with restoring the computer to working condition.
This lock is by design. It allows the owner to prevent anyone that can’t prove they own the hardware from getting Apple or other service professionals to erase the lock.
See https://www.apple.com/icloud/find-my-iphone/ and especially the Mac link at the bottom.
You now have a firmware password on that Mac preventing you from changing the OS to boot from other sources. You can either enter the passcode that was created to lock the hardware or follow the normal process when you forget a firmware password by seeking authorized service.