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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-91685	AIX7-00-003124	SV-101783r1_rule		Medium

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.

STIG	Date
IBM AIX 7.x Security Technical Implementation Guide	2020-02-24

Details

Check Text ( C-90839r3_chk )
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.

Check Text ( C-90839r3_chk )

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 Text (F-97883r1_fix)
Edit the "/etc/hosts.allow" and "/etc/hosts.deny" files to configure access restrictions. Add "ALL: ALL" entry to "/etc/hosts.deny" file.