DISA STIGS Viewer

OL 9 must be configured so that successful/unsuccessful uses of the umount2 system call generate an audit record.

Overview

Finding ID Version Rule ID IA Controls Severity
V-271595 OL09-00-000845 SV-271595r1092584_rule   Medium
Description
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing discretionary access control (DAC) modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
STIG Date
Oracle Linux 9 Security Technical Implementation Guide 2025-05-08

Details

Check Text (C-75645r1091495_chk)
Verify that OL 9 generates an audit record for all uses of the umount2 system call with the following commands:

$ sudo grep "umount2" /etc/audit/audit.rules

$ sudo sh -c 'grep "umount2" /etc/audit/audit.rules'

If the system is configured to audit this activity, it will return a line.

If no line is returned, this is a finding.
Fix Text (F-75552r1092583_fix)
Configure the audit system to generate an audit event for any successful/unsuccessful use of the umount2 system call by adding the following rules to a rules file in /etc/audit/rules.d/ directory: (Example /etc/audit/rules.d/audit.rules)

-a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod
-a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod

The audit daemon must be restarted for the changes to take effect.

Restart auditd:
$ sudo service auditd restart