STIGQter: STIG Summary: Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide Version: 1 Release: 1 Benchmark Date: 26 Mar 2026:

A TOSS 5 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems.

DISA Rule

SV-282675r1201005_rule

Vulnerability Number

V-282675

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

TOSS-05-000194

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

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 the TOSS 5 "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

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 TOSS 5 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding.

Vulnerability Number

V-282675

Documentable

False

Rule Version

TOSS-05-000194

Severity Override Guidance

Verify the TOSS 5 "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

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 TOSS 5 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding.

Check Content Reference

M

Target Key

5738