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Guide to the Secure Configuration of Ubuntu 20.04

Rules, Groups, and Values defined within the XCCDF Benchmark

  • 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 comma-delimited list of command specifications. T...
    Rule Medium Severity
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  • 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 explicitly list the runas spec (i.e. the list of targe...
    Rule Medium Severity
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  • System Tooling / Utilities

    The following checks evaluate the system for recommended base packages -- both for installation and removal.
    Group
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  • Ensure gnutls-utils is installed

    The gnutls-utils package can be installed with the following command: 
    $ apt-get install gnutls-utils
    Rule Medium Severity
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  • Ensure nss-tools is installed

    The nss-tools package can be installed with the following command: 
    $ apt-get install nss-tools
    Rule Medium Severity
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  • Ensure apt_get Removes Previous Package Versions

    <code>apt_get</code> should be configured to remove previous software components after new versions have been installed. To configure <code>apt_get</code> to remove the previous software component...
    Rule Low Severity
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  • 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 that account has access. Therefore, making it mor...
    Group
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  • 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 like parentheses and quotation marks must be escap...
    Value
    Show

  • 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 like parentheses and quotation marks must be escap...
    Value
    Show

  • 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 like parentheses and quotation marks must be escap...
    Value
    Show

  • Modify the System Login Banner for Remote Connections

    To configure the system login banner edit <code>/etc/issue.net</code>. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is ...
    Rule Medium Severity
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  • Verify Group Ownership of System Login Banner

    To properly set the group owner of /etc/issue, run the command: 
    $ sudo chgrp root /etc/issue
    Rule Medium Severity
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  • Verify Group Ownership of System Login Banner for Remote Connections

    To properly set the group owner of /etc/issue.net, run the command: 
    $ sudo chgrp root /etc/issue.net
    Rule Medium Severity
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  • Verify Group Ownership of Message of the Day Banner

    To properly set the group owner of /etc/motd, run the command: 
    $ sudo chgrp root /etc/motd
    Rule Medium Severity
    Show

  • Verify ownership of System Login Banner

    To properly set the owner of /etc/issue, run the command: 
    $ sudo chown root /etc/issue
    Rule Medium Severity
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  • Verify ownership of System Login Banner for Remote Connections

    To properly set the owner of /etc/issue.net, run the command: 
    $ sudo chown root /etc/issue.net
    Rule Medium Severity
    Show

  • Verify ownership of Message of the Day Banner

    To properly set the owner of /etc/motd, run the command: 
    $ sudo chown root /etc/motd
    Rule Medium Severity
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  • Verify permissions on System Login Banner

    To properly set the permissions of /etc/issue, run the command: 
    $ sudo chmod 0644 /etc/issue
    Rule Medium Severity
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  • Verify permissions on System Login Banner for Remote Connections

    To properly set the permissions of /etc/issue.net, run the command: 
    $ sudo chmod 0644 /etc/issue.net
    Rule Medium Severity
    Show

  • 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 (GDM). The warning banner should be displayed in t...
    Group
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  • Set the GNOME3 Login Warning Banner Text

    In the default graphical environment, configuring the login warning banner text in the GNOME Display Manager's login screen can be configured on the login screen by setting <code>banner-message-tex...
    Rule Medium Severity
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  • Password Hashing algorithm

    Specify the system default encryption algorithm for encrypting passwords. Defines the value set as ENCRYPT_METHOD in /etc/login.defs.
    Value
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  • 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 alternating between the same password too frequen...
    Value
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  • Install pam_pwquality Package

    The libpam-pwquality package can be installed with the following command: 
    $ apt-get install libpam-pwquality
    Rule Medium Severity
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  • 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/sudo" file with the following command: <pre>$ sudo...
    Rule Medium Severity
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  • fail_deny

    Number of failed login attempts before account lockout
    Value
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  • fail_interval

    Interval for counting failed login attempts before account lockout
    Value
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  • fail_unlock_time

    Seconds before automatic unlocking or permanently locking after excessive failed logins
    Value
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  • faildelay_delay

    Delay next login attempt after a failed login
    Value
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  • pwhistory_remember

    Prevent password re-use using password history lookup
    Value
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  • tally2

    Number of failed login attempts
    Value
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  • Account Lockouts Must Be Logged

    PAM faillock locks an account due to excessive password failures, this event must be logged.
    Rule Medium Severity
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  • Account Lockouts Must Persist

    By setting a `dir` in the faillock configuration account lockouts will persist across reboots.
    Rule Medium Severity
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  • Limit Password Reuse

    Do not allow users to reuse recent passwords. This can be accomplished by using the remember option for the pam_unix or pam_pwhistory PAM modules.
    Rule Medium Severity
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  • Enforce Delay After Failed Logon Attempts

    To configure the system to introduce a delay after failed logon attempts, add or correct the <code>pam_faildelay</code> settings in <code>/etc/pam.d/common-auth</code> to make sure its <code>delay<...
    Rule Medium Severity
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  • Account Lockouts Must Be Logged

    PAM faillock locks an account due to excessive password failures, this event must be logged.
    Rule Medium Severity
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  • Set Password Quality Requirements

    The default <code>pam_pwquality</code> PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of...
    Group
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  • dcredit

    Minimum number of digits in password
    Value
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  • dictcheck

    Prevent the use of dictionary words for passwords.
    Value
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  • difok

    Minimum number of characters not present in old password
    Value
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  • lcredit

    Minimum number of lower case in password
    Value
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  • minclass

    Minimum number of categories of characters that must exist in a password
    Value
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  • minlen

    Minimum number of characters in password
    Value
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  • ocredit

    Minimum number of other (special characters) in password
    Value
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  • retry

    Number of retry attempts before erroring out
    Value
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  • ucredit

    Minimum number of upper case in password
    Value
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  • Ensure PAM Enforces Password Requirements - Prevent the Use of Dictionary Words

    The pam_pwquality module's dictcheck check if passwords contains dictionary words. When dictcheck is set to 1 passwords will be checked for dictionary words.
    Rule Medium Severity
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  • Ensure PAM Enforces Password Requirements - Enforcing

    Verify that the operating system uses "pwquality" to enforce the password complexity rules. Verify the pwquality module is being enforced by operating system by running the following command: <pre...
    Rule Medium Severity
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  • Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters

    The pam_pwquality module's <code>lcredit</code> parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain...
    Rule Medium Severity
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  • Ensure PAM Enforces Password Requirements - Minimum Different Categories

    The pam_pwquality module's <code>minclass</code> parameter controls requirements for usage of different character classes, or types, of character that must exist in a password before it is consider...
    Rule Medium Severity
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Node 2

siemur/test-space

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.

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