The Red Hat Enterprise Linux operating system access control program must be configured to grant or deny system access to specific hosts and services.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-72315	RHEL-07-040810	SV-86939r3_rule		Medium

Description
If the systems access control program is not configured with appropriate rules for allowing and denying access to system network resources, services may be accessible to unauthorized hosts.

STIG	Date
Red Hat Enterprise Linux 7 Security Technical Implementation Guide	2019-03-08

Details

Check Text ( C-72549r3_chk )
If the "firewalld" package is not installed, ask the System Administrator (SA) if another firewall application (such as iptables) is installed. If an application firewall is not installed, this is a finding. Verify the system's access control program is configured to grant or deny system access to specific hosts. Check to see if "firewalld" is active with the following command: # systemctl status firewalld firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled) Active: active (running) since Sun 2014-04-20 14:06:46 BST; 30s ago If "firewalld" is active, check to see if it is configured to grant or deny access to specific hosts or services with the following commands: # firewall-cmd --get-default-zone public # firewall-cmd --list-all --zone=public public (active) target: default icmp-block-inversion: no interfaces: eth0 sources: services: mdns ssh ports: protocols: masquerade: no forward-ports: icmp-blocks: If "firewalld" is not active, determine whether "tcpwrappers" is being used by checking whether the "hosts.allow" and "hosts.deny" files are empty with the following commands: # ls -al /etc/hosts.allow rw-r----- 1 root root 9 Aug 2 23:13 /etc/hosts.allow # ls -al /etc/hosts.deny -rw-r----- 1 root root 9 Apr 9 2007 /etc/hosts.deny If "firewalld" and "tcpwrappers" are not installed, configured, and active, ask the SA if another access control program (such as iptables) is installed and active. Ask the SA to show that the running configuration grants or denies access to specific hosts or services. If "firewalld" is active and is not configured to grant access to specific hosts or "tcpwrappers" is not configured to grant or deny access to specific hosts, this is a finding.

Check Text ( C-72549r3_chk )

If the "firewalld" package is not installed, ask the System Administrator (SA) if another firewall application (such as iptables) is installed. If an application firewall is not installed, this is a finding.

Verify the system's access control program is configured to grant or deny system access to specific hosts.

Check to see if "firewalld" is active with the following command:

# systemctl status firewalld
firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
Active: active (running) since Sun 2014-04-20 14:06:46 BST; 30s ago

If "firewalld" is active, check to see if it is configured to grant or deny access to specific hosts or services with the following commands:

# firewall-cmd --get-default-zone
public

# firewall-cmd --list-all --zone=public
public (active)
target: default
icmp-block-inversion: no
interfaces: eth0
sources:
services: mdns ssh
ports:
protocols:
masquerade: no
forward-ports:
icmp-blocks:

If "firewalld" is not active, determine whether "tcpwrappers" is being used by checking whether the "hosts.allow" and "hosts.deny" files are empty with the following commands:

# ls -al /etc/hosts.allow
rw-r----- 1 root root 9 Aug 2 23:13 /etc/hosts.allow

# ls -al /etc/hosts.deny
-rw-r----- 1 root root 9 Apr 9 2007 /etc/hosts.deny

If "firewalld" and "tcpwrappers" are not installed, configured, and active, ask the SA if another access control program (such as iptables) is installed and active. Ask the SA to show that the running configuration grants or denies access to specific hosts or services.

If "firewalld" is active and is not configured to grant access to specific hosts or "tcpwrappers" is not configured to grant or deny access to specific hosts, this is a finding.

Fix Text (F-78669r3_fix)
If "firewalld" is installed and active on the system, configure rules for allowing specific services and hosts. If "firewalld" is not "active", enable "tcpwrappers" by configuring "/etc/hosts.allow" and "/etc/hosts.deny" to allow or deny access to specific hosts.