STIGQter: STIG Summary: Oracle Linux 9 Security Technical Implementation Guide Version: 1 Release: 6 Benchmark Date: 01 Jul 2026:

OL 9 must be configured so that the firewall employs a deny-all, allow-by-exception policy for allowing connections to other systems.

DISA Rule

SV-271473r1091131_rule

Vulnerability Number

V-271473

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

OL09-00-000224

Severity

CAT II

CCI(s)

CCI-000366 - Implement the security configuration settings.

Weight

Fix Recommendation

Configure the firewalld daemon to employ a deny-all, allow-by-exception with the following commands:

Start by adding the exceptions that are required for mission functionality to the "drop" zone. If SSH access on port 22 is needed, for example, run the following: "sudo firewall-cmd --permanent --add-service=ssh --zone=drop"

Reload the firewall rules to update the runtime configuration from the "--permanent" changes made above:
$ sudo firewall-cmd --reload

Set the default zone to the drop zone:
$ sudo firewall-cmd --set-default-zone=drop
Note: This is a runtime and permanent change.

Add any interfaces to the newly modified "drop" zone:
$ sudo firewall-cmd --permanent --zone=drop --change-interface=ens33

Reload the firewall rules for changes to take effect:
$ sudo firewall-cmd --reload

Check Contents

Verify that OL 9 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
public
interfaces: ens33

$ sudo firewall-cmd --info-zone=public | grep target
target: DROP

$ sudo firewall-cmd --permanent --info-zone=public | grep target
target: DROP

If no zones are active on the OL 9 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding.

Vulnerability Number

V-271473

Documentable

False

Rule Version

OL09-00-000224

Severity Override Guidance

Check Content Reference

Target Key

5680