Skip to content

Guide to the Secure Configuration of Ubuntu 20.04

Rules, Groups, and Values defined within the XCCDF Benchmark

  • Verify iptables Enabled

    The iptables service can be enabled with the following command:
    $ sudo systemctl enable iptables.service
    Rule Medium Severity
  • Set Default ip6tables Policy for Incoming Packets

    To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in <code>/etc/sysconfig/ip6tables</code>: <pre...
    Rule Medium Severity
  • Set configuration for IPv6 loopback traffic

    Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.
    Rule Medium Severity
  • Set configuration for loopback traffic

    Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.
    Rule Medium Severity
  • Disable IPv6 Addressing on IPv6 Interfaces by Default

    To disable support for (<code>ipv6</code>) addressing on interfaces by default add the following line to <code>/etc/sysctl.d/ipv6.conf</code> (or another file in <code>/etc/sysctl.d</code>): <pre>n...
    Rule Medium Severity
  • Set Default iptables Policy for Incoming Packets

    To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in <code>/etc/sysconfig/iptables</code>: <pre>...
    Rule Medium Severity
  • Set Default iptables Policy for Forwarded Packets

    To set the default policy to DROP (instead of ACCEPT) for the built-in FORWARD chain which processes packets that will be forwarded from one interface to another, add or correct the following line ...
    Rule Medium Severity
  • IPv6

    The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important featu...
    Group
  • Disable Support for IPv6 Unless Needed

    Despite configuration that suggests support for IPv6 has been disabled, link-local IPv6 address auto-configuration occurs even when only an IPv4 address is assigned. The only way to effectively pre...
    Group
  • Disable IPv6 Networking Support Automatic Loading

    To prevent the IPv6 kernel module (<code>ipv6</code>) from binding to the IPv6 networking stack, add the following line to <code>/etc/modprobe.d/disabled.conf</code> (or another file in <code>/etc/...
    Rule Medium Severity
  • net.ipv6.conf.default.accept_source_route

    Trackers could be using source-routed packets to generate traffic that seems to be intra-net, but actually was created outside and has been redirected.
    Value
  • Disable Accepting ICMP Redirects for All IPv6 Interfaces

    To set the runtime status of the <code>net.ipv6.conf.all.accept_redirects</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0</pre> To mak...
    Rule Medium Severity
  • Disable Kernel Parameter for IPv6 Forwarding

    To set the runtime status of the <code>net.ipv6.conf.all.forwarding</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.ipv6.conf.all.forwarding=0</pre> To make sure that ...
    Rule Medium Severity
  • Disable Accepting Router Advertisements on all IPv6 Interfaces by Default

    To set the runtime status of the <code>net.ipv6.conf.default.accept_ra</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.ipv6.conf.default.accept_ra=0</pre> To make sure...
    Rule Medium Severity
  • Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces

    To set the runtime status of the <code>net.ipv6.conf.default.accept_redirects</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0</pre...
    Rule Medium Severity
  • Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default

    To set the runtime status of the <code>net.ipv6.conf.default.accept_source_route</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=...
    Rule Medium Severity
  • net.ipv4.conf.default.secure_redirects

    Enable to prevent hijacking of routing path by only allowing redirects from gateways known in routing table. Disable to refuse acceptance of secure ICMP redirected packages by default.
    Value
  • Kernel Parameters Which Affect Networking

    The sysctl utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.
    Group
  • Network Related Kernel Runtime Parameters for Hosts and Routers

    Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.
    Group
  • net.ipv4.conf.all.accept_redirects

    Disable ICMP Redirect Acceptance
    Value

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