Linux - Copied from midterm review (answers)

Question 1

For hardening purposes, what is the primary benefit of having the file /etc/shadow?

Answer 1

It stores encrypted user passwords, making them unreadable directly.

Question 2

Which of the following represents the symbolic permission to give the owner read and write access, the group only read access, and others no access?

Answer 2

u=rw,g=r,o=-

Question 3

If a Linux file has the permissions -rw-r–r–, who has the ability to write to the file?

Answer 3

Only the owner

Question 4

Which of the following files contains encrypted passwords of users?

Answer 4

/etc/shadow

Question 5

Setting the ‘s’ bit on a file in the user ownership does which of the following:

Answer 5

All processes created using that file run with the user ownership of the command file

Question 6

To be able to change into directory Dir1, what is the minimum permissions necessary for the Dir1 directory?

Answer 6

Execute (x)

Question 7

What is the octal permission of a directory that allows the owner to access files if they know their names, but not to list or to change the file names?

Answer 7

100

Question 8

Setting the ‘s’ bit on a directory in the group ownership does which of the following:

Answer 8

All files created in that directory will have the same group ownership as the parent directory

Question 9

The UID and GID for a user can be found in which file?

Answer 9

/etc/passwd

Question 10

The /etc/group file contains information about:

Answer 10

Group memberships

Question 11

For system hardening purposes, how can an administrator restrict a specific user from using the sudo command to gain superuser privileges?

Answer 11

Explicitly deny the user in the /etc/sudoers file or associated configurations.

Question 12

In the context of Linux access controls, what does DAC stand for?

Answer 12

Discretionary Access Control

Question 13

Setting the ‘s’ bit on a file in the group ownership does which of the following:

Answer 13

All processes created using that file run with the group ownership of the command file

Question 14

In an empty directory, you run the commands: touch ??? * ; chmod 111 * chmod 444 ??? ; chmod 666 ‘*’ ; chmod 333 * What permissions are on file ??? after above commands?

Answer 14

-wx -wx -wx

Question 15

What is the octal mode of a directory that allows only the user to cd into it and list the names in it and create any new files?

Answer 15

700

Question 16

Which command is used to change the ownership of a file in Linux?

Answer 16

chown

Question 17

Which of the following commands is used to show the user’s own identity and group information?

Answer 17

id

Question 18

Which of the following commands can be used to change the ownership of a file in Linux?

Answer 18

chown

Question 19

Which file in Linux contains the encrypted passwords of users?

Answer 19

/etc/shadow

Question 20

Which command is used to modify an existing user’s information in Linux?

Answer 20

usermod

Question 21

Which of the following commands is used to change a user’s default login shell?

Answer 21

chsh

Question 22

In the file /etc/group, what does the last field represent?

Answer 22

List of users

Question 23

What is the easiest way for root to allow a regular user in Red Hat Enterprise Linux to run any administrator commands with sudo?

Answer 23

Add the user to the wheel group

Question 24

What value of umask gives the permissions below to a new file: rw-rw-r–

Answer 24

2

Question 25

You are working at the Linux command line and your username is “homer”. You execute the command ls and see the following output: -rw-rw-r-- 1 homer homer 387 Nov 28 08:26 bigfoot -rwxr-xr-x 1 homer homer 1851882 Nov 28 08:26 dragon -rwxrwxr-x 1 homer homer 15957213 Nov 28 08:26 kraken What command can you type which will remove execute permission from the file dragon for all users except yourself?

Answer 25

chmod 744 dragon

Question 26

Refer to the exhibit above. What would be the permissions of f1.txt after executing the last command?

Answer 26

700

Question 27

When hardening a server system, which account should have its direct login access blocked?

Answer 27

Root user

Question 28

In a Linux system, which account type is created for running specific services or applications?

Answer 28

System users

Question 29

If an administrator wants to efficiently manage multiple users' default settings upon creation, which directory plays a critical role?

Answer 29

/etc/skel

Question 30

What Linux command can be used to set the default permissions for all newly created files?

Answer 30

umask

Question 31

Which command allows you to view the groups a user belongs to?

Answer 31

id

Question 32

If an administrator wishes to prevent a specific user from using the sudo command, they should edit which file?

Answer 32

/etc/sudoers

Question 33

What command is used to create a new group?

Answer 33

groupadd

Question 34

To ensure a user cannot directly log into the system, which shell should be assigned in /etc/passwd?

Answer 34

/bin/nologin

Question 35

In a multi-user GNU/Linux environment, which command is the safest to use when changing a user's default shell?

Answer 35

chsh

Question 36

What Linux command can be used to change the group of a file?

Answer 36

chgrp

Question 37

You are working at the Linux command line. What command can you type which will result in a new file being given the following permissions by default: - The file owner can read and write to the file, but not execute it. - Everyone other than the owner can read the file, but not write to or execute it.

Answer 37

umask 133

Question 38

The filename /etc/passwd is a(n) _________________.

Answer 38

Absolute path

Question 39

Which of the following is not true of the root user?

Answer 39

The root user can access any computer on the network.

Question 40

Which Access Control Technique is based on security labels and is mandatory regardless of the user's wishes?

Answer 40

MAC