Guide to the Secure Configuration of Ubuntu 16.04
Rules, Groups, and Values defined within the XCCDF Benchmark
-
Ensure /home Located On Separate Partition
If user home directories will be stored locally, create a separate partition for <code>/home</code> at installation time (or migrate it later using...Rule Low Severity -
Ensure /srv Located On Separate Partition
If a file server (FTP, TFTP...) is hosted locally, create a separate partition for <code>/srv</code> at installation time (or migrate it later usin...Rule Unknown Severity -
Ensure /tmp Located On Separate Partition
The <code>/tmp</code> directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at...Rule Low Severity -
Ensure /var Located On Separate Partition
The <code>/var</code> directory is used by daemons and other system services to store frequently-changing data. Ensure that <code>/var</code> has i...Rule Low Severity -
Ensure /var/log Located On Separate Partition
System logs are stored in the <code>/var/log</code> directory. Ensure that <code>/var/log</code> has its own partition or logical volume at instal...Rule Low Severity -
Ensure /var/log/audit Located On Separate Partition
Audit logs are stored in the <code>/var/log/audit</code> directory. Ensure that <code>/var/log/audit</code> has its own partition or logical volum...Rule Low Severity -
GNOME Desktop Environment
GNOME is a graphical desktop environment bundled with many Linux distributions that allow users to easily interact with the operating system graphi...Group -
Configure GNOME Login Screen
In the default GNOME desktop, the login is displayed after system boot and can display user accounts, allow users to reboot the system, and allow u...Group -
Disable XDMCP in GDM
XDMCP is an unencrypted protocol, and therefore, presents a security risk, see e.g. <a href="https://help.gnome.org/admin/gdm/stable/security.html....Rule High Severity -
Don't define allowed commands in sudoers by means of exclusion
Policies applied by sudo through the sudoers file should not involve negation. Each user specification in the <code>sudoers</code> file contains a...Rule Medium Severity -
Sudo - timestamp_timeout value
Defines the number of minutes that can elapse before <code>sudo</code> will ask for a passwd again. If set to a value less than 0 the user's time s...Value -
Sudo - umask value
Specify the sudo umask to use. The actual umask value that is used is the union of the user's umask and the sudo umask. The default sudo umask is 0...Value -
Ensure Privileged Escalated Commands Cannot Execute Other Commands - sudo NOEXEC
The sudo <code>NOEXEC</code> tag, when specified, prevents user executed commands from executing other commands, like a shell for example. This sho...Rule High Severity -
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo requiretty
The sudo <code>requiretty</code> tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by...Rule Medium Severity -
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty
The sudo <code>use_pty</code> tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by ma...Rule Medium Severity -
Ensure Sudo Logfile Exists - sudo logfile
A custom log sudo file can be configured with the 'logfile' tag. This rule configures a sudo custom logfile at the default location suggested by CI...Rule Low Severity -
Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticate
The sudo <code>!authenticate</code> option, when specified, allows a user to execute commands using sudo without having to authenticate. This shoul...Rule Medium Severity -
Ensure Users Re-Authenticate for Privilege Escalation - sudo NOPASSWD
The sudo <code>NOPASSWD</code> tag, when specified, allows a user to execute commands using sudo without having to authenticate. This should be dis...Rule Medium Severity -
Ensure Users Re-Authenticate for Privilege Escalation - sudo
The sudo <code>NOPASSWD</code> and <code>!authenticate</code> option, when specified, allows a user to execute commands using sudo without having t...Rule Medium Severity -
Only the VDSM User Can Use sudo NOPASSWD
The sudo <code>NOPASSWD</code> tag, when specified, allows a user to execute commands using sudo without having to authenticate. Only the <code>vds...Rule Medium Severity -
Explicit arguments in sudo specifications
All commands in the sudoers file must strictly specify the arguments allowed to be used for a given user. If the command is supposed to be executed...Rule Medium Severity -
Action for auditd to take when disk space is low
The setting for admin_space_left_action in /etc/audit/auditd.confValue -
Hardware Tokens for Authentication
The use of hardware tokens such as smart cards for system login provides stronger, two-factor authentication than using a username and password. I...Group -
Don't target root user in the sudoers file
The targeted users of a user specification should be, as much as possible, non privileged users (i.e.: non-root). User specifications have to expl...Rule Medium Severity -
System Tooling / Utilities
The following checks evaluate the system for recommended base packages -- both for installation and removal.Group -
Ensure gnutls-utils is installed
Thegnutls-utilspackage can be installed with the following command:$ apt-get install gnutls-utils
Rule Medium Severity -
Ensure nss-tools is installed
Thenss-toolspackage can be installed with the following command:$ apt-get install nss-tools
Rule Medium Severity -
Updating Software
The <code>apt_get</code> command line tool is used to install and update software packages. The system also provides a graphical software update to...Group -
Ensure Software Patches Installed
If the system has an apt repository available, run the following command to install updates: <pre>$ apt update && apt full-upgrade</pre> ...Rule Medium Severity -
Account and Access Control
In traditional Unix security, if an attacker gains shell access to a certain login account, they can perform any action or access any file to which...Group -
Authselect profile
Specify the authselect profile to selectValue -
Warning Banners for System Accesses
Each system should expose as little information about itself as possible. <br><br> System banners, which are typically displayed just before a logi...Group -
Login Banner Verbiage
Enter an appropriate login banner for your organization. Please note that new lines must be expressed by the '\n' character and special characters ...Value -
MotD Banner Verbiage
Enter an appropriate login banner for your organization. Please note that new lines must be expressed by the '\n' character and special characters ...Value -
Remote Login Banner Verbiage
Enter an appropriate login banner for your organization. Please note that new lines must be expressed by the '\n' character and special characters ...Value -
Implement a GUI Warning Banner
In the default graphical environment, users logging directly into the system are greeted with a login screen provided by the GNOME Display Manager ...Group -
Account Lockouts Must Persist
By setting a `dir` in the faillock configuration account lockouts will persist across reboots.Rule Medium Severity -
Protect Accounts by Configuring PAM
PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and confi...Group -
Password Hashing algorithm
Specify the system default encryption algorithm for encrypting passwords. Defines the value set as ENCRYPT_METHOD in /etc/login.defs.Value -
remember
The last n passwords for each user are saved in <code>/etc/security/opasswd</code> in order to force password change history and keep the user from...Value -
Disallow Configuration to Bypass Password Requirements for Privilege Escalation
Verify the operating system is not configured to bypass password requirements for privilege escalation. Check the configuration of the "/etc/pam.d/...Rule Medium Severity -
Set Lockouts for Failed Password Attempts
The <code>pam_faillock</code> PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentati...Group -
fail_deny
Number of failed login attempts before account lockoutValue -
faillock directory
The directory where the user files with the failure records are keptValue -
fail_interval
Interval for counting failed login attempts before account lockoutValue -
fail_unlock_time
Seconds before automatic unlocking or permanently locking after excessive failed loginsValue -
tally2_unlock_time
Seconds before automatic unlocking or permanently locking after excessive failed loginsValue -
faildelay_delay
Delay next login attempt after a failed loginValue -
pwhistory_remember
Prevent password re-use using password history lookupValue -
PAM pwhistory remember - control flag
'Specify the control flag required for password remember requirement. If multiple values are allowed write them separated by commas as in "required...Value
Node 2
The content of the drawer really is up to you. It could have form fields, definition lists, text lists, labels, charts, progress bars, etc. Spacing recommendation is 24px margins. You can put tabs in here, and can also make the drawer scrollable.