I’ll share a story about how macOS passwords can be easily reset, so we should set firmware passwords as a countermeasure.
Background: Mac Passwords Can Be Easily Reset...
I heard the scary story that “if a Mac is stolen, passwords can be easily reset,” so I’ll introduce password reset methods and countermeasures.
Password Reset Method: resetpassword from Terminal
If you can't log in with the new password after restarting your Mac, follow these additional steps:
- Restart again, then immediately press and hold Command-R or other macOS Recovery key combinations until you see the Apple logo or spinning globe, then release.
- When the "macOS Utilities" window appears, choose Utilities > Terminal from the menu bar.
- In the Terminal window, type "resetpassword" and press Return to open the "Reset Password" assistant shown above.
- Select "Password doesn't work when logging in" and click Next, then follow the onscreen instructions for your user account.
Source: Change or reset the password of a macOS user account - Apple Support (macOS ユーザアカウントのパスワードを変更またはリセットする - Apple サポート)
Countermeasure: Set Firmware Password
- Set a firmware password on your Mac - Apple Support (Mac でファームウェアパスワードを設定する - Apple サポート)
That’s all from the Gemba on wanting to take countermeasures so that resetpassword cannot be used if a Mac is stolen.