Cracking Ubuntu/Linux Root Password

 

Reset Your Forgotten Ubuntu Password in 2 Minutes or Less

If you’ve ever forgotten your password, you aren’t alone… it’s probably one of the most common tech support problems I’ve encountered over the years. Luckily if you are using Ubuntu they made it incredibly easy to reset your password.

All it takes is adjusting the boot parameters slightly and typing a command or two, but we’ll walk you through it.

Reset Your Ubuntu Password

Reboot your computer, and then as soon as you see the GRUB Loading screen, make sure to hit the ESC key so that you can get to the menu.

Root Shell – Easy Method

If you have the option, you can choose the “recovery mode” item on the menu, usually found right below your default kernel option.



Then choose “Drop to root shell prompt” from this menu.


This should give you a root shell prompt.

Alternate Root Shell Method

If you don’t have the recovery mode option, this is the alternate way to manually edit the grub options to allow for a root shell.

First you’ll want to make sure to choose the regular boot kernel that you use (typically just the default one), and then use the “e” key to choose to edit that boot option.


Now just hit the down arrow key over to the “kernel” option, and then use the “e” key to switch to edit mode for the kernel option.



You’ll first be presented with a screen that looks very similar to this one:


You’ll want to remove the “ro quiet splash” part with the backspace key, and then add this onto the end:
  
rw init=/bin/bash 

Once you hit enter after adjusting the kernel line, you’ll need to use the B key to choose to boot with that option.

At this point the system should boot up very quickly to a command prompt.


Changing the Actual Password
You can use the following command to reset your password:

passwd <username>

For example my username being geek I used this command:

passwd geek

After changing your password, use the following commands to reboot your system. (The sync command makes sure to write out data to the disk before rebooting)

sync
reboot –f

I found that the –f parameter was necessary to get the reboot command to work for some reason. You could always hardware reset instead, but make sure to use the sync command first.

Follow the steps from above till getting into the root shell i.e command line interface then, if u want to add a new username & password just follow the instructions here :

Create a new username in ubuntu linux from command line

Adding a new user :
enter : 
$ sudo adduser <anything>

Set or Change User Password 

Type passwd command as follows to change your own password:

$ passwd

Output:

Changing password for vivek
(current) UNIX password:
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

The user is first prompted for his/her old password, if one is present. This password is then encrypted and compared against the stored password. The user has only one chance to enter the correct password. The super user is permitted to bypass this step so that forgotten passwords may be changed.

A new password is tested for complexity. As a general guideline, passwords should consist of 6 to 8 characters including one or more from each of following sets:

1. Lower case alphabetics
2. Upper case alphabetics
3. Digits 0 thru 9
4. Punctuation marks

Task: Change Password For Other User Account

You must login as root user, type the following command to change password for user vivek:

# passwd vivek

 
Output:

Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

Where,

• vivek - is username or account name.

YOU SHUD REMEMBER THE MAIN STEP AFTER PERFORMING ALL OPERATIONS:
/* After changing your password, use the following commands to reboot your system. (The sync command makes sure to write out data to the disk before rebooting)/*

sync
reboot –f

And now you should be able to login without any issues.