7.1.4 Ensure Audit bin(ary) audit event collection is configured

Information

This recommendation configures AIX auditing in bin mode.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

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 auditlv -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 * * * * /etc/security/aixpert/bin/cronaudit

NOTE: The implementation of a script to suit internal security policy is recommended to further enhance the log rotation process.

Add the audit startup command into /etc/inittab :

mkitab "audit:2:boot:audit start > /dev/console 2>&amp;1 # Start audit"

See Also

https://workbench.cisecurity.org/benchmarks/10385

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-2

Plugin: Unix

Control ID: cc43129b76b7bf23be9b808b638eb1f483d635c1a01d1b21669ea71ed6b977af