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6.3.3.17 Ensure successful and unsuccessful attempts to use the chacl command are collected

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

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Information

The operating system must generate audit records for successful/unsuccessful uses of the chacl command.

chacl is an IRIX-compatibility command, and is maintained for those users who are familiar with its use from either XFS or IRIX.

chacl changes the ACL(s) for a file or directory. Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit records can be generated from various components within the information system (e.g., module or policy filter).

Solution

Create audit rules

Edit or create a file in the /etc/audit/rules.d/ directory, ending in .rules extension, with the relevant rules to monitor successful and unsuccessful attempts to use the chacl command.

Example:

# {
 UID_MIN=$(awk '/^\s*UID_MIN/{print $2}' /etc/login.defs)
 [ -n "${UID_MIN}" ] && printf "
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=${UID_MIN} -F auid!=unset -k perm_chng
" >> /etc/audit/rules.d/50-perm_chng.rules || printf "ERROR: Variable 'UID_MIN' is unset.\n"
}

Load audit rules

Merge and load the rules into active configuration:

# augenrules --load

Check if reboot is required.

# if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi

See Also

https://workbench.cisecurity.org/benchmarks/18208

Item Details

References: CSCv7|6.2

Plugin: Unix

Control ID: e85396606f0c6b4f96e0920c6deee06f18d727e81aa9164b13e823d39eeffaa4