Linux Superuser password cracking and protection through grub

Password cracking through grub

Start the computer and enter the following interface

Select the selected option and press e.

Select the selected option and press e.

Insert single into the original sentence by modifying the cursor below)

After modification, press enter, press B to enter the following interface, and enter the passwd root command, enter the new password and enter the new password again, and press enter to confirm

Restart your computer to log on with the new password.

Protection: set a password for grub

Open the terminal and enter grub

Press enter and enter md5crypt.

Press enter, enter the desired password, and press enter to get "ciphertext"

Open another terminal window

Enter cd \ boot \ grub

Edit the menu. lst file in the grub directory --> command: vi menu. lst

Input an empty line on the first title:

Passwd -- md5 ciphertext

Save the disk and exit, so that grub is encrypted

To restart the computer and try grub again to crack the superuser password, enter the password