5.1 Basic Security and Identifying User Types Flashcards
Security
all system-local user account POSIX other than pw readable by all
/etc/pswd
Security
all system-local group account POSIC readable by all
/etc/group
Security
all system-local user pw hashes and expiration info - unreadable by any - only select processes.
/etc/shadow
Security
all system-local priv escalation info/allowance by sudo command
/etc/sudoers
Security
list real or effective user and group IDs
id
Security
list users who logged in last
last
Security
list users who are currently logged in
who
Security
similar to who but with additional context
w
Security
switch to another user with a login shell or run commands as that user by passing that user’s pw
su
Security
switch User or Superuser Do - if entitled, the current user enters their own pw if required to raise priv
sudo
Security
change user’s shell
chsh
Security
change user’s info on the GECOS field
chfn
Security
The UID and GID attributes are stored
/etc/passwd
Security
The Groups attribute is stored
/etc/group
Security
where is the has user password stored
/etc/shadow
Security
cryptography used by default to store p/w locally on inux
one-way hash
Security
If an account has a User ID (UID) enumerated under 1000, what type of account is this?
system account
Security
How can you get a list of the active logins in your system, and a count of them as well?
Use the w command. Besides a list of all active logins, it will also show information like how
many users are logged in, along the system load and uptime.
Security
commands to list current users logged into the system
w
who
Security
command to list users that have disconnected.
last
Security
What is the difference between the w and the who command
w command lists system utilization while who does not.
Security
w command no header option
-h
Security
w command short option
-s
Security
w command ip address option
-i
Security
file that stores a user’s one-way password hash
/etc/shadow
Security
file that contains a list of groups a user account is a member of
/etc/group
Security
What logic can be used to compile a list of groups a user account is a member of?
/etc/group
Security
how to change current user’s login shell to Korn Shell (/usr/bin/ksh) in non-interactive mode?
chsh -s /usr/bin/ksh
Security
why is the home directory of the root user not placed within the /home directory
because root account is required to troubleshoot and fix errors and may include file system issues related to /home directory and in such cases root should be fully functional even when /home file system is not available yet.
