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Guide to the Secure Configuration of Red Hat Enterprise Linux CoreOS 4

Rules, Groups, and Values defined within the XCCDF Benchmark

  • Ensure /var/log/audit Located On Separate Partition

    Audit logs are stored in the <code>/var/log/audit</code> directory. <p> Partitioning Red Hat CoreOS is a Day 1 operation and cannot be changed afterwards. For documentation on how to add a MachineC...
    Rule Low Severity
  • Ensure /var/tmp Located On Separate Partition

    The /var/tmp directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
    Rule Medium 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 graphically rather than textually. The GNOME Graphical D...
    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 users to login automatically and/or with a guest ac...
    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.en_GB#xdmcpsecurity">XDMCP Gnome docs</a>. To dis...
    Rule High Severity
  • Group name dedicated to the use of sudo

    Specify the name of the group that should own /usr/bin/sudo.
    Value
  • Sudo - logfile value

    Specify the sudo logfile to use. The default value used here matches the example location from CIS, which uses /var/log/sudo.log.
    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 0022. This guarantess sudo never lowers the umask w...
    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 should be enabled by making sure that the <code>NOEXE...
    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 making sure that the <code>requiretty</code> tag ...
    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 making sure that the <code>use_pty</code> tag exists...
    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 disabled by making sure that the <code>NOPASSWD</code...
    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 to authenticate. This should be disabled by making ...
    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>vdsm</code> user should have this capability in any s...
    Rule Medium 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 comma-delimited list of command specifications. T...
    Rule Medium Severity
  • 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
  • System Tooling / Utilities

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

    The nss-tools package can be installed with the following command:
    $ sudo dnf install nss-tools
    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 that account has access. Therefore, making it mor...
    Group
  • 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 login prompt, give out information about the s...
    Group

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