Successful/unsuccessful uses of the fchmodat command must generate an audit record.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-75741	UBTU-16-020580	SV-90421r4_rule		Medium

Description
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). Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215

Description

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). Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215

STIG	Date
Canonical Ubuntu 16.04 Security Technical Implementation Guide	2019-12-23

Details

Check Text ( C-75427r3_chk )
Verify the Ubuntu operating system generates an audit record when successful/unsuccessful attempts to use the "fchmodat" command occur. Check that the following calls are being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": # sudo grep -w fchmodat /etc/audit/audit.rules -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng If the command does not return a line, or the line is commented out, this is a finding.

Check Text ( C-75427r3_chk )

Verify the Ubuntu operating system generates an audit record when successful/unsuccessful attempts to use the "fchmodat" command occur.

Check that the following calls are being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules":

# sudo grep -w fchmodat /etc/audit/audit.rules

-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng

If the command does not return a line, or the line is commented out, this is a finding.

Fix Text (F-82369r3_fix)
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchmodat" command by adding the following lines to "/etc/audit/audit.rules": -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: # sudo systemctl restart auditd.service

Fix Text (F-82369r3_fix)

Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchmodat" command by adding the following lines to "/etc/audit/audit.rules":

-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_chng

The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command:

# sudo systemctl restart auditd.service