Successful/unsuccessful uses of the umount2 system call in RHEL 9 must generate an audit record.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258216	RHEL-09-654210	SV-258216r958412_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 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

Description

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing 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
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2024-06-04

Details

Check Text ( C-61957r926633_chk )
To determine if the system is configured to audit calls to the umount2 system call, run the following command: $ sudo grep "umount2" /etc/audit/audit.* 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-61881r926634_fix)
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount2" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory: -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.

Fix Text (F-61881r926634_fix)

Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount2" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory:

-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.