Attempted to set Grub Password and now cannot log in. Help!

General system Kernel, boot, graphics & hardware
1

Hello, I used this guide here to set a grub password.

I did this on two different computers. On one, I had the superuser left as admin and it worked just fine. But with my other computer I used a different superuser. Now when I try and get past grub at boot it just does not let me proceed even when I enter correct username and password. Not sure where to go from here. Any help is highly appreciated!

2

Hi @goldfish

Note: Live ISO + chroot = your GRUB password is bypassed. Anyone with physical access can access your system unless you have LUKS encryption and even a BIOS password. GRUB password alone won’t protect against that.

If your non-standard username isn’t working, here’s the fix:

  1. Boot a live ISO

  2. Mount your root partition: sudo mount /dev/sdXN /mnt

  3. sudo chroot /mnt

  4. Edit the config: nano /etc/grub.d/40_custom

  5. Make sure set superusers="yourname" and password_pbkdf2 yourname ... match exactly

  6. update-grub

  7. exit and reboot

example /etc/grub.d/40_custom

set superusers=“john”
password_pbkdf2 john grub.pbkdf2.sha512.10000…