IBM AIX
TMA-AIX-8.1.1
Ensure /audit filesystem has been created and configured
Description
This recommendation provides guidance for preparing an AIX system to operate with AUDIT active. AIX Audit has been available as part of the kernel since 1995. The historical setup has all of it's files in the root partition. This presents a risk that / (/dev/hd4) may be (nearly) full and impact system availability. Audit: checks the /audit filesystem, mkuser.default auditclasses, the cronaudit job and the inittab audit entry; review /etc/security/audit/config manually.
How it is checked
Audit method: Shell command
command -v lsfs >/dev/null 2>&1 || exit 1; command -v lssec >/dev/null 2>&1 || exit 1; command -v lsitab >/dev/null 2>&1 || exit 1; r=compliant; lsfs /audit >/dev/null 2>&1 || r="Audit Filesystem is missing"; a=$(lssec -f /usr/lib/security/mkuser.default -s user -a auditclasses 2>/dev/null); [ "$a" = "user auditclasses=general,SRC,cron,tcpip" ] || r="mkuser.default: $a"; crontab -l 2>/dev/null | grep -q cronaudit || r="cronaudit cron job missing"; lsitab audit >/dev/null 2>&1 || r="audit inittab entry missing"; echo "$r"- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
Configure AIX auditing in-line with the High Level AIX Security Expert policy. Create a /audit filesystem, at least 100 MB in size: mklv -y <LV name> -t jfs2 -u 1 -c 1 rootvg 1 hdisk0 crfs -v jfs2 -d <LV name> -m /audit -A yes -t no mount /audit Reflect the following configuration in the /etc/security/audit/config file: vi /etc/security/audit/config Add in: start: binmode = on streammode = off bin: trail = /audit/trail bin1 = /audit/bin1 bin2 = /audit/bin2 binsize = 10240 cmds = /etc/security/audit/bincmds Add the auditing entries for root and all other users below the pre-defined audit classes: users: root = general,SRC,mail,cron,tcpip,ipsec,lvm <user 1> = general,SRC,cron,tcpip <user 2> = general,SRC,cron,tcpip etc. Update the /usr/lib/security/mkuser.default auditclasses entry to ensure that auditing is set up for any newly created users: chsec -f /usr/lib/security/mkuser.default -s user -a auditclasses=general,SRC,cron,tcpip A cron job is implemented to monitor the free space in /audit, running hourly, to ensure that /audit does not fill up. If /audit is greater than 90% used, /audit/trail is moved to /audit/trailOneLevelBack: crontab -e Add in: 0 * ... (see CIS section 8.1.1)
Properties
- Operating systems
- Any
- Tags
- aixaudit
- Reference
- CIS IBM AIX 7 Benchmark v1.2.0 - 8.1.1 Ensure /audit filesystem has been created and configured
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target aix --level 2