Linux system hack Login password

　

Method One:

GRUB: On the boot loader menu, type [e] to enter edit mode. You will face a list of boot projects. Look for a line that resembles the following output: kernel/vmlinuz-2.4.18-0.4 ro root=/dev/hda2 Press the arrow key until the line is highlighted, and then press [E]. You can now empty a box at the end of the text and add a single to tell the GRUB boot-user Linux mode. Press the [Enter] key to make the edit result effective. You will be brought to the edit mode screen, from here, press grub to boot single-user Linux mode. After loading, you will face a shell hint similar to the following: sh-2.05# now, you can change the root command, type: bash# passwd root You will be asked to retype the password to verify. After the end, the password will be changed, you can type reboot at the prompt to reboot, and then, as usual, log on as the root user. Lil when the system boots to the Lilo boot screen, press TAB to enter text mode for the graphical boot mode, then enter the Linux single carriage return at Lilo to enter the password-free console, and then use the passwd command to change the root password.

Method Two:grub->linux-> Select the middle---E---> after the prompt input (/Linux s init 1)-Enter after--b--> restart, after the prompt input (vi/etc/passwd And the user's password transfer bits (x) removed, forced to save)----Restart!

This is the most common and quickest way.

Prevent others from changing passwords in single-user mode.

Because you want to boot single-user mode, you need to edit it in grub. As a result, we can prevent grub by encrypting it and not letting others modify it.

Here's how:

1. Grub has a configuration file in/etc in this folder. The name is "grub.conf", find this file, edit it with VI.

2, we look at the contents of the document: (the note will be waived)

Default=0

timeout=10

Splashimage= (hd0,0)/grub/splash.xpm.gz

Title Red Hat Linux (2.4.20-8)

Root (hd0,0)

Kernel/vmlinuz-2.4.20-8 ro root=label=/

Initrd/initrd-2.4.20-8.img

Specific meaning you can view the following grub related documents, here we need to add the password.

There are two places where you can add a password.

3, the first place is "timeout=10" the following, here Add "password=123456" (123456 is their own password). Save, exit, restart. As we can see, it is not possible to modify the "E" on the Grub interface. If you want to modify it, you must press "P" to enter the password.

4, the second place is "initrd/initrd-2.4.20-8.img" below. Add "password=123456" here (123456 is your own password). Save, exit, restart. We can see that there is one more password before Linux starts (over the Grub interface). It is important to note that this password prevents single-user mode from entering. That is, even if we start single-user mode by editing grub, we still need to enter this password.

How to hack the grub password to get user privileges

To get the grub password, we have to find a way to read the grub.conf file. But no grub password, no root password ... So we can't boot through grub.

Here's how:

1, first to modify the startup mode of this virtual machine, we need to boot from the CD. Instead, the virtual machine defaults to the hard drive as the first boot mode.

When the virtual machine starts (the big "VMware" interface) Press "F2" to enter the BIOS immediately.

2, select to boot that column. Select the "CD-ROM Drive" and press "+" to elevate the CD-ROM to the top. This will start the system on the default disc as the first boot mode.

3, the first Linux installation disk image binding CD-ROM drive, save, restart. The system will go directly to the Linux installation interface. Enter "Linux Rescue" at the prompt and the system will start the Linux rescue mode.

4, on the way there will be several options, follow the prompts to choose just fine. Finally, you will see a note that the rescue system has attached the original system file (the one on the hard disk) to the "/mnt/sysimage" folder.

5, after the launch, we can look for grub.conf files. Note the structure of the folder below: We are now in the root directory of the rescue system. And we are looking for the original system of "/etc/grub.conf", so the complete path is: "/mnt/sysimage/etc/grub.conf". Edit this file with VI and we can see and modify the file. To break down the grub password.

Prevent others from booting to Linux rescue mode.

We can see that the BIOS must be modified to boot into rescue mode. Then we can use the BIOS encryption to prevent others from modifying the BIOS, so as not to boot from the CD.

Here's how:

This is relatively simple. Select the "Security" entry after entering the BIOS. Enter on "Set Supervisor Password". Set the password on it. Such We need a password when we restart the system to enter the BIOS again.

How to hack the BIOS password

What method do we often use to clear the host BIOS password? Unplug the jumper, keying the battery, and let the BIOS restore the factory settings. So, is there a similar method on a virtual machine?

Here's how:

Locate the folder where the virtual machine is located, and there should be a file with a suffix of ". Nvram". Erase the file. Start the system. We can see. The BIOS is reset.

This article is from the "Lonely No Color" blog, please be sure to keep this source http://tenderness.blog.51cto.com/8855468/1942957

Linux system hack Login password