Turn your computer on.
Press ESC at the grub prompt.
Press e for edit.
Highlight the line that begins kernel ………, press e
Go to the very end of the line, add rw init=/bin/bash
press enter, then press b to boot your system.
Your system will boot up to a passwordless root shell.
Type in passwd username
Set your password.
Type in reboot
If this doesnt work you can alternatively try this:
Turn on your computer, and as soon as you the Press Esc to enter grub message, press the escape key.
Select the option that says (recovery mode).
Your PC will boot into a shell. Once you get a command prompt, type "passwd username" where the username is your username.
Enter a new password when prompted, and again when prompted again
Type reboot to reboot your system
Another way is to boot into the system via a live cd open up Applications->Accessories->Terminal
then mount your ubuntu drive if its on /dev/sda1 do this:
mount /dev/sda1/ /media/sda1
Then we chroot into the system:
chroot /media/sda1passwd userNow change the password, and reboot your box!
um, how is this not a security vulnerability?
ReplyDeleteThis is not a security vulnerability, no system is safe howsoever strong the security is, if the hacker has physical access to machine.
ReplyDeleteyou can even change the root password by booting into single user mode through LIVE CD, this is not a security flaw, its a back-door recovery system.
If you don't trust people who have phisycal access to your box, you should set a bios password. Bios has an optional password for this reason.
ReplyDeleteDon't think bios passwords are perfect, either. If you open up the case, there is a set of jumpers on the motherboard to reset the bios password in case you get locked out. All it takes is a set of house keys to short out the terminals and you're in the system in a heartbeat.
ReplyDeleteBIOS passwords are NOT secure in any way.
Once again, I support what has been said by others -- Any machine of which is given physical access to people has security vulnerabilities regardless of how locked down the system is by remote.
Matt
There is no such thing as a secure computer.
ReplyDeleteEven if it's unplugged, turned off, locked inside a safe, buried in the ground in a spot patrolled by armed guards and vicious dogs.
There is always a way to compromise a system. Security is not a switch, it's a mindset.
so whats the point of having a password?
ReplyDeleteIs there a windows equivalent for that?
For the best system security you should use full disk encryption via the Ubuntu Alternate Install CD (http://news.softpedia.com/news/Encrypted-Ubuntu-7-10-68383.shtml).
ReplyDeleteyes there is a windows equivelent to cracking if u wanna call it that ..
ReplyDeleteYou get a disk you can download off the net called Hiren' boot disk (google it) write that iso to a disk..booot pc with it and run its password recovery tools..
bam u have changed the admin password or another password..
Bios have backdoor passwords also.
ReplyDelete