TMA-AIX-3.1

Ensure default user umask is configured

MediumLevel 1Automatedaix

Description

The user file-creation mode mask (umask) is used to determine the file permission for newly created directories and files. In AIX, the default permissions for any newly created directory is 0755 (rwxr-xr-x), and for any newly created file it is 0644 (rw-r--r--). The umask modifies the default AIX permissions by restricting (masking) these permissions. Audit: automated read-only check derived from the CIS audit procedure; it prints "compliant" when the control is met.

How it is checked

Audit method: Shell command

shell

command -v lssec >/dev/null 2>&1 || exit 1; out=$(lssec -f /etc/security/user -s default -a umask 2>/dev/null) || exit 1; printf '%s\n' "$out" | grep -Eq "^default umask=[0-7]?[2367]7$" && echo compliant || echo "$out"

Expected output: compliant

How it is fixed

Fix method: Shell command

shell

chsec -f /etc/security/user -s default -a umask=027

Properties

Operating systems: Any
Tags: aixaccounts
Reference: CIS IBM AIX 7 Benchmark v1.2.0 - 3.1 Ensure default user umask is configured

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target aix