OpenControls Logo

STIG Viewer

STIGViewer Support

A RHEL 8 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-230504RHEL-08-040090SV-230504r958672_ruleCCI-002314medium
Description
Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DoD data. RHEL 8 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be utilized to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection.
STIGDate
Red Hat Enterprise Linux 8 Security Technical Implementation Guide2026-02-05

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

NET-14.1Automated Monitoring & Control
1.00
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (22) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-17(1)Monitoring and Control
1.00
AC-17(2)Protection of Confidentiality and Integrity Using Encryption
1.00
AC-17(9)Disconnect or Disable Access
1.00
AC-18(1)Authentication and Encryption
1.00
AC-2(1)Automated System Account Management
1.00
AC-3Access Enforcement
1.00
AU-12Audit Record Generation
1.00
AU-3Content of Audit Records
1.00
CA-3(5)Restrictions on External System Connections
1.00
CM-5(1)Automated Access Enforcement and Audit Records
1.00

+12 more (top 10 by confidence shown)

NIST 800-1710 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

3.1.12
1.00
CCI1 mapping
CCI-002314
1.00

Details

Check Text (C-230504r958672_chk)

Verify "firewalld" is configured to employ a deny-all, allow-by-exception policy for allowing connections to other systems with the following commands: $ sudo firewall-cmd --state running $ sudo firewall-cmd --get-active-zones [custom] interfaces: ens33 $ sudo firewall-cmd --info-zone=[custom] | grep target target: DROP If no zones are active on the RHEL 8 interfaces or if the target is set to a different option other than "DROP", this is a finding. If the "firewalld" package is not installed, ask the System Administrator if an alternate firewall (such as iptables) is installed and in use, and how is it configured to employ a deny-all, allow-by-exception policy. If the alternate firewall is not configured to employ a deny-all, allow-by-exception policy, this is a finding. If no firewall is installed, this is a finding.

Fix Text (F-33148r942941_fix)

Configure the "firewalld" daemon to employ a deny-all, allow-by-exception with the following commands: $ sudo firewall-cmd --permanent --new-zone=[custom] $ sudo cp /usr/lib/firewalld/zones/drop.xml /etc/firewalld/zones/[custom].xml This will provide a clean configuration file to work with that employs a deny-all approach. Note: Add the exceptions that are required for mission functionality and update the short title in the xml file to match the [custom] zone name. Reload the firewall rules to make the new [custom] zone available to load: $ sudo firewall-cmd --reload Set the default zone to the new [custom] zone: $ sudo firewall-cmd --set-default-zone=[custom] Note: This is a runtime and permanent change. Add any interfaces to the new [custom] zone: $ sudo firewall-cmd --permanent --zone=[custom] --change-interface=ens33 Reload the firewall rules for changes to take effect: $ sudo firewall-cmd --reload