diff --git a/linux_os/guide/system/network/network-ufw/ufw_only_required_services/rule.yml b/linux_os/guide/system/network/network-ufw/ufw_only_required_services/rule.yml new file mode 100644 index 000000000000..bfebb3f51456 --- /dev/null +++ b/linux_os/guide/system/network/network-ufw/ufw_only_required_services/rule.yml @@ -0,0 +1,73 @@ +documentation_complete: true + +prodtype: ubuntu2004 + +title: 'Only Allow Authorized Network Services in ufw' + +description: |- + Check the firewall configuration for any unnecessary or prohibited + functions, ports, protocols, and/or services by running the following + command: +
$ sudo ufw show raw + Chain OUTPUT (policy ACCEPT) + target prot opt sources destination + Chain INPUT (policy ACCEPT 1 packets, 40 bytes) + pkts bytes target prot opt in out source destination + Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) + pkts bytes target prot opt in out source destination + Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) + pkts bytes target prot opt in out source destination+ + Ask the System Administrator for the site or program PPSM CLSA. Verify + the services allowed by the firewall match the PPSM CLSA. + +rationale: |- + To prevent unauthorized connection of devices, unauthorized transfer of + information, or unauthorized tunneling (i.e., embedding of data types + within data types), organizations must disable or restrict unused or + unnecessary physical and logical ports/protocols on information systems. + + Operating systems are capable of providing a wide variety of functions + and services. Some of the functions and services provided by default + may not be necessary to support essential organizational operations. + Additionally, it is sometimes convenient to provide multiple services + from a single component (e.g., VPN and IPS); however, doing so + increases risk over limiting the services provided by any one component. + + To support the requirements and principles of least functionality, the + operating system must support the organizational requirements, providing + only essential capabilities and limiting the use of ports, protocols, + and/or services to only those required, authorized, and approved to + conduct official business or to address authorized quality of life + issues. + +platforms: + - var_ufw + - machine + +severity: medium + +references: + disa: CCI-000382 + srg: SRG-OS-000096-GPOS-00050 + stigid@ubuntu2004: UBTU-20-010407 + +ocil_clause: 'unauthorized network services can be accessed from the network' + +ocil: |- + Check the firewall configuration for any unnecessary or prohibited + functions, ports, protocols, and/or services by running the following + command: +
$ sudo ufw show raw+ + Ask the System Administrator for the site or program PPSM CLSA. Verify + the services allowed by the firewall match the PPSM CLSA. + + Add all ports, protocols, or services allowed by the PPSM CLSA by using + the following command: +
$ sudo ufw allow "direction" "port/protocol/service"+ where the direction is "in" or "out" and the port is the one + corresponding to the protocol or service allowed. + + To deny access to ports, protocols, or services, use: +
$ sudo ufw deny "direction" "port/protocol/service"