Disable an Open Firmware (EFI) password on an Intel Mac

Ok, so you thought it would be a good idea to secure your Mac using a firmware password, and then you forgot it. Or, alternatively, you left your machine logged in and an enterprising and mischievous co-worker set a password while you were away. In either scenario, you’re confronted with the same problem: you can’t do anything but boot normally unless you enter the password to unlock the firmware.

If you’re running Leopard, the latest release of OS X from Apple, the solution is actually quite easy. As with most Apple stuff, the firmware password seems really secure, but it’s not, since Apple has nicely built in a backdoor. Here’s what you’ll need: your computer, a Leopard install disk or original system disk, and an administrative account on the Mac you’re unlocking. Got it? Ok, let’s get started:

  1. Boot normally into Mac OS X. You should be able to do this, because you’re not changing any boot options.
  2. Insert the OS X Leopard DVD into your computer. The popup will appear asking to install OS X. Just ignore or close it.
  3. Open Terminal by going to Applications -> Utilities -> Terminal or typing ‘Terminal’ into Spotlight.
  4. Enter the following: open /Volumes/Mac\ OS\ X\ Install\ DVD/Applications
  5. In the Finder window that opens, choose Utilities and then Firmware Password Utility. Uncheck the box to set the firmware password and hit Change. Your password is now reset to blank, and you won’t be prompted to enter one when changing boot options.

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Comments

Dexter (Mar 03, 2010)

Perfect, It's Work

Don Quijote (Oct 03, 2010)

Thank you! This worked great!

Scot (Nov 12, 2010)

I notice that by having the EFI Firmware password in place, holding down the C Key at boot up is disabled, what do I do in the event my OSX installation becomes corrupt and I need to boot off my Snow Leopard disc again to reinstall the OS, is this now impossible to do ?. Its an Intel based mac I have btw running Snow Leopard

vaskenhauri (Nov 15, 2010)

@Scot,

As far as I remember, the workaround described in this article will allow you to boot off the CD without entering the EFI password. Can you try the instructions and let folks know whether they still work?

vaskenhauri (Nov 15, 2010)

@Scot,

As far as I remember, the workaround described in this article will allow you to reset the EFI password. Can you try the instructions and let folks know whether they still work?

Richard (Nov 25, 2010)

If you have the Firmware password holding down option during boot will still work. Otherwise try the above.

If you don't have the password and your OS is corrupt and the above does not work:
1. Change your memory size. ( Add/Remove one stick)
2. Boot doing a PR Reset.
3. Turn off computer.
4. Boot from CD normally.

Guest (Feb 23, 2011)

Thanks Richard works perfect.