Break through the root user's skills through Grub in Linux

Article Title: Tips for breaking through the root user through Grub in Linux. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

The grub settings are described as follows:

Default = 1

Timeout = 10

Splashimage = (hd0, 2)/grub/splash.xpm.gz

Hiddenmenu

Title Fedora

Root (hd0, 2)

Kernel/vmlinuz-2.6.23.1-42.fc8 ro root =/dev/VolGroup00/LogVol00 rhgb quiet

Initrd/initrd-2.6.23.1-42.fc8.img

Title Windows

Rootnoverify (hd0, 0)

Chainloader + 1

Enable the computer. On the gurb Boot Loader menu, select Fedora and type [e] to enter the editing mode.

A list of pilot projects is displayed. Find the following output sentence lines:

Kernel/vmlinuz-2.6.23.1-42.fc8 ro root =/dev/VolGroup00/LogVol00 rhgb quiet

Press the arrow key until the line is highlighted, and then press [e]. Now you can add a single entry at the end of the text to tell grub to guide the single-user Linux mode.

Press the [Enter] key to make the editing result take effect. You will be taken with the edit mode screen. From here, press B and grub will guide the single-user Linux mode.

After loading, you will face a shell prompt similar to the following: sh-3.2 #

The single-user mode is equivalent to the Windows security mode. Only the root user has "#"!

Sh-3.2 # vi/etc/passwd

Only the first line in passwd is mentioned here.

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

Here, "x" indicates that the root password is removed from "x" and changed

Root: 0: 0: root:/bin/bash

Sh-3.2 # vi/etc/shadow

Similarly, modify the first line in shadow.

Root: $1 $ 3YjH4woI $ 49jmwaejd9roj1_g3yo7j.: 13928: 0: 99999: 7 :::

Remove the root password and change it

Root: 13928: 0: 99999: 7 :::

When you exit, you must use wq!

In this way, the root user has no password. Starting from the computer, it broke through the root user.