How to break linux password
 

if you forget your root password and can't get access to your machine here is the solution:

1- when you get into GRUP boot loader ,and when the highlight is on linux Press 'a' .

to get into rescue mode press space and enter '1' at the end of the line:

root ...................... LABLE:/ 1

then press 'b' to boot

2- when you get into black screen with cursor, write down the command:

# passwd

enter your password

#exit

to exit the rescue mode

and have fun.....

you can also hit "a" and boot to single user mode by typing space single. From there you can modify the passwd by removing the x (which signifies the password)
i.e.

root:x:0:0:root:/root:/bin/bash

This will set the password to blank for any account you reset.

Can do basically the same thing by booting in single user mode with lilo....

Just another way to do the same thing :)

and this is why we all set GRUB boot loader passwords when we setup our servers... right kids... right.

loooooooooooooooooooooooooooooooolzzz
but also we can boot from bootable CD reinstall grub and have fun ....... :))

you can force single user mode to ask for roots password before alowing access.

Some distro's do this by default. Such as SuSE. which I discovered to my peril. Until about the 7th hour, when I suddenly remembered what it was ;)

There are docs on tldp.org about securing single user mode.

Thats also why we all set BIOS passwords... right kids... right.

thanks teacccheerr

Umm, BIOS passwords are circumventable. A secured linux box is not. Hell you can show me any windows system and I can easily break into it via changing the Admin password.

There's even a widly distributed linux boot disk that changes the MS-Windows Administrator password to one of your choosing ;) But you wont find one for *NIX

Good ways to secure your machine from the above techniques listed above:

1. Don't give any unauthorized person physical access to the machines.
2. Don't forget your own or root's password.

I think that's all..

;)