Check: TOSS-04-030470
Tri-Lab Operating System Stack (TOSS) 4 STIG:
TOSS-04-030470
(in versions v1 r3 through v1 r1)
Title
Successful/unsuccessful uses of the "unlinkat" command in TOSS must generate an audit record. (Cat II impact)
Discussion
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). The "unlinkat" system call operates in exactly the same way as either "unlink" or "rmdir" except for the differences described in the manual page. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1." The AUID representation is an unsigned 32-bit integer, which equals "4294967295." The audit system interprets "-1", "4294967295", and "unset" in the same way. 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-000468-GPOS-00212, SRG-OS-000471-GPOS-00215
Check Content
Verify that an audit event is generated for any successful/unsuccessful use of the "unlinkat" command by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "unlinkat" /etc/audit/audit.rules -a always,exit -F arch=b32 -S unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlinkat -F auid>=1000 -F auid!=unset -k delete If the command does not return a line, or the line is commented out, this is a finding.
Fix Text
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "unlinkat" syscall by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlinkat -F auid>=1000 -F auid!=unset -k delete The audit daemon must be restarted for the changes to take effect.
Additional Identifiers
Rule ID: SV-253001r824327_rule
Vulnerability ID: V-253001
Group Title: SRG-OS-000037-GPOS-00015
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000130 |
The information system generates audit records containing information that establishes what type of event occurred. |
CCI-000135 |
The information system generates audit records containing the organization-defined additional, more detailed information that is to be included in the audit records. |
CCI-000169 |
The information system provides audit record generation capability for the auditable events defined in AU-2 a. at organization-defined information system components. |
CCI-000172 |
The information system generates audit records for the events defined in AU-2 d. with the content defined in AU-3. |
CCI-002884 |
The organization audits nonlocal maintenance and diagnostic sessions^ organization-defined audit events. |