Successful/unsuccessful uses of the umount2 system call in TOSS 5 must generate an audit record.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-282423 | SRG-OS-000037-GPOS-00015 | TOSS-05-000451 | SV-282423r1201569_rule | 2026-04-01 | 1 |
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-000477-GPOS-00222
ℹ️ Check
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 no line is returned, this is a finding.
✔️ 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
Restart the audit daemon for changes to take effect.