The Photon operating system must audit all account removal actions.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258834	SRG-OS-000241-GPOS-00091	PHTN-40-000078	SV-258834r991553_rule	2024-07-11	2

Description
When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes.

Description

When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes.

ℹ️ Check
At the command line, run the following command to verify an audit rule exists to audit account removals: # auditctl -l \| grep -E "(userdel\|groupdel)" Example result: -w /usr/sbin/userdel -p x -k userdel -w /usr/sbin/groupdel -p x -k groupdel If either "userdel" or "groupdel" are not listed with a permissions filter of at least "x", this is a finding. Note: This check depends on the "auditd" service to be in a running state for accurate results. The "auditd" service is enabled in control PHTN-40-000016.

ℹ️ Check

At the command line, run the following command to verify an audit rule exists to audit account removals: # auditctl -l | grep -E "(userdel|groupdel)" Example result: -w /usr/sbin/userdel -p x -k userdel -w /usr/sbin/groupdel -p x -k groupdel If either "userdel" or "groupdel" are not listed with a permissions filter of at least "x", this is a finding. Note: This check depends on the "auditd" service to be in a running state for accurate results. The "auditd" service is enabled in control PHTN-40-000016.

✔️ Fix
Navigate to and open: /etc/audit/rules.d/audit.STIG.rules Add or update the following lines: -w /usr/sbin/userdel -p x -k userdel -w /usr/sbin/groupdel -p x -k groupdel At the command line, run the following command to load the new audit rules: # /sbin/augenrules --load Note: An "audit.STIG.rules" file is provided with this guidance for placement in "/etc/audit/rules.d" that contains all rules needed for auditd. Note: An older "audit.STIG.rules" may exist and may reference older "GEN" SRG IDs. This file can be removed and replaced as necessary with an updated one.

✔️ Fix

Navigate to and open: /etc/audit/rules.d/audit.STIG.rules Add or update the following lines: -w /usr/sbin/userdel -p x -k userdel -w /usr/sbin/groupdel -p x -k groupdel At the command line, run the following command to load the new audit rules: # /sbin/augenrules --load Note: An "audit.STIG.rules" file is provided with this guidance for placement in "/etc/audit/rules.d" that contains all rules needed for auditd. Note: An older "audit.STIG.rules" may exist and may reference older "GEN" SRG IDs. This file can be removed and replaced as necessary with an updated one.