UIDs reserved for system accounts must not be assigned to non-system accounts on AIX systems.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-215195 | AIX7-00-001036 | SV-215195r991589_rule | CCI-000366 | medium |
| Description | ||||
| Reserved UIDs are typically used by system software packages. If non-system accounts have UIDs in this range, they may conflict with system software, possibly leading to the user having permissions to modify system files. | ||||
| STIG | Date | |||
| IBM AIX 7.x Security Technical Implementation Guide | 2024-08-16 | |||
Details
Check Text (C-215195r991589_chk)
Check the UID assignments of all accounts using:
# more /etc/passwd
root:!:0:0::/root:/usr/bin/ksh
daemon:!:1:1::/etc:
bin:!:2:2::/bin:
sys:!:3:3::/usr/sys:
adm:!:4:4::/var/adm:
nobody:!:4294967294:4294967294::/:
invscout:*:6:12::/var/adm/invscout:/usr/bin/ksh
srvproxy:*:203:0:Service Proxy Daemon:/home/srvproxy:/usr/bin/ksh
esaadmin:*:7:0::/var/esa:/usr/bin/ksh
sshd:*:212:203::/var/empty:/usr/bin/ksh
doej:*:704:1776::/home/doej:/usr/bin/ksh
Confirm all accounts with a UID of 128 and below are used by a system account.
If a UID reserved for system accounts (0-128) is used by a non-system account, this is a finding.
Fix Text (F-16391r294037_fix)
Using the "usermod" command, change the UID numbers for non-system accounts with reserved UIDs (those less or equal to 128):
# usermod -u <uid> [user_name]