Skip to content
ATO Pathways
  Log In

Guide to the Secure Configuration of Ubuntu 20.04

Rules, Groups, and Values defined within the XCCDF Benchmark

  • Verify Permissions on SSH Server Private *_key Key Files

    SSH server private keys - files that match the <code>/etc/ssh/*_key</code> glob, have to have restricted permissions. If those files are owned by t...
    Rule Medium Severity
    Show

  • Verify Permissions on SSH Server Public *.pub Key Files

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

  • Remove SSH Server iptables Firewall exception (Unusual)

    By default, inbound connections to SSH's port are allowed. If the SSH server is not being used, this exception should be removed from the firewall ...
    Rule Unknown Severity
    Show

  • Configure OpenSSH Client if Necessary

    The following configuration changes apply to the SSH client. They can improve security parameters relwevant to the client user, e.g. increasing ent...
    Group
    Show

  • Configure OpenSSH Server if Necessary

    If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file <code>/etc/ssh/sshd_confi...
    Group
    Show

  • SSH RekeyLimit - size

    Specify the size component of the rekey limit.
    Value
    Show

  • SSH RekeyLimit - size

    Specify the size component of the rekey limit.
    Value
    Show

  • SSH Compression Setting

    Specify the compression setting for SSH connections.
    Value
    Show

  • SSH Privilege Separation Setting

    Specify whether and how sshd separates privileges when handling incoming network connections.
    Value
    Show

  • SSH LoginGraceTime setting

    Configure parameters for how long the servers stays connected before the user has successfully logged in
    Value
    Show

  • SSH MaxStartups setting

    Configure parameters for maximum concurrent unauthenticated connections to the SSH daemon.
    Value
    Show

  • Set SSH Client Alive Count Max

    The SSH server sends at most <code>ClientAliveCountMax</code> messages during a SSH session and waits for a response from the SSH client. The optio...
    Rule Medium Severity
    Show

  • Set SSH Client Alive Interval

    SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automat...
    Rule Medium Severity
    Show

  • Allow Only SSH Protocol 2

    Only SSH protocol version 2 connections should be permitted. The default setting in <code>/etc/ssh/sshd_config</code> is correct, and can be verifi...
    Rule High Severity
    Show

  • Disable Compression Or Set Compression to delayed

    Compression is useful for slow network connections over long distances but can cause performance issues on local LANs. If use of compression is req...
    Rule Medium Severity
    Show

  • Disable SSH Support for Rhosts RSA Authentication

    SSH can allow authentication through the obsolete rsh command through the use of the authenticating user's SSH keys. This should be disabled. <br><...
    Rule Medium Severity
    Show

  • Enable Use of Strict Mode Checking

    SSHs <code>StrictModes</code> option checks file and ownership permissions in the user's home directory <code>.ssh</code> folder before accepting l...
    Rule Medium Severity
    Show

  • Enable SSH Warning Banner

    To enable the warning banner and ensure it is consistent across the system, add or correct the following line in <code>/etc/ssh/sshd_config.d/00-...
    Rule Medium Severity
    Show

  • Enable SSH Warning Banner

    To enable the warning banner and ensure it is consistent across the system, add or correct the following line in <code>/etc/ssh/sshd_config</code>...
    Rule Medium Severity
    Show

  • Enable Encrypted X11 Forwarding

    By default, remote X11 connections are not encrypted when initiated by users. SSH has the capability to encrypt remote X11 connections when SSH's <...
    Rule High Severity
    Show

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.

Capacity
Modules