STIGQter: STIG Summary: Oracle Linux 6 Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 23 Apr 2021:

The audit system must be configured to audit all discretionary access control permission modifications using fchmod.

DISA Rule

SV-208895r603263_rule

Vulnerability Number

V-208895

Group Title

SRG-OS-000064

Rule Version

OL6-00-000186

Severity

CAT III

CCI(s)

• CCI-000172 - The information system generates audit records for the events defined in AU-2 d. with the content defined in AU-3.

Weight

10

Fix Recommendation

At a minimum, the audit system should collect file permission changes for all users and root. Add the following to "/etc/audit/audit.rules":

-a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b32 -S fchmod -F auid=0 -k perm_mod

If the system is 64-bit, then also add the following:

-a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b64 -S fchmod -F auid=0 -k perm_mod

Check Contents

To determine if the system is configured to audit calls to the "fchmod" system call, run the following command:

$ sudo grep -w "fchmod" /etc/audit/audit.rules

-a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b32 -S fchmod -F auid=0 -k perm_mod
-a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b64 -S fchmod -F auid=0 -k perm_mod

If the system is 64-bit and does not return a rule for both "b32" and "b64" architectures, this is a finding.

If the system is not configured to audit the "fchmod" system call, this is a finding.

Vulnerability Number

V-208895

Documentable

False

Rule Version

OL6-00-000186

Severity Override Guidance

To determine if the system is configured to audit calls to the "fchmod" system call, run the following command:

$ sudo grep -w "fchmod" /etc/audit/audit.rules

-a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b32 -S fchmod -F auid=0 -k perm_mod
-a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 \
-k perm_mod
-a always,exit -F arch=b64 -S fchmod -F auid=0 -k perm_mod

If the system is 64-bit and does not return a rule for both "b32" and "b64" architectures, this is a finding.

If the system is not configured to audit the "fchmod" system call, this is a finding.

Check Content Reference

M

Target Key

2928

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