The AIX systems access control program must be configured to grant or deny system access to specific hosts.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-215419	SRG-OS-000480-GPOS-00227	AIX7-00-003124	SV-215419r991589_rule	2024-08-16	3

Description
If the system's 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.

ℹ️ Check
Check for the existence of the "/etc/hosts.allow" and "/etc/hosts.deny" files using commands: # ls -la /etc/hosts.allow -rw-r--r-- 1 root system 11 Jan 28 11:09 /etc/hosts.allow # ls -la /etc/hosts.deny -rw-r--r-- 1 root system 0 Jan 28 11:02 /etc/hosts.deny If either file does not exist, this is a finding. Check for the presence of a default deny entry using command: # grep -E "ALL:[[:blank:]]*ALL" /etc/hosts.deny ALL:ALL If the "ALL: ALL" entry is not present in the "/etc/hosts.deny" file, any TCP service from a host or network not matching other rules will be allowed access. If the entry is not in "/etc/hosts.deny", this is a finding.

ℹ️ Check

Check for the existence of the "/etc/hosts.allow" and "/etc/hosts.deny" files using commands: # ls -la /etc/hosts.allow -rw-r--r-- 1 root system 11 Jan 28 11:09 /etc/hosts.allow # ls -la /etc/hosts.deny -rw-r--r-- 1 root system 0 Jan 28 11:02 /etc/hosts.deny If either file does not exist, this is a finding. Check for the presence of a default deny entry using command: # grep -E "ALL:[[:blank:]]*ALL" /etc/hosts.deny ALL:ALL If the "ALL: ALL" entry is not present in the "/etc/hosts.deny" file, any TCP service from a host or network not matching other rules will be allowed access. If the entry is not in "/etc/hosts.deny", this is a finding.

✔️ Fix
Edit the "/etc/hosts.allow" and "/etc/hosts.deny" files to configure access restrictions. Add "ALL: ALL" entry to "/etc/hosts.deny" file.