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>&1 # Start audit"