SV-226313r852148: The system must generate an audit event when the audit log reaches a percentage of full threshold. | Microsoft Windows Server 2012/2012 R2 Domain Controller STIG SCAP Benchmark

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Assessment Title

Rule Text

The system must generate an audit event when the audit log reaches a percentage of full threshold.

Description

Discussion Text

When the audit log reaches a given percent full, an audit event is written to the security log. It is recorded as a successful audit event under the category of System. This option may be especially useful if the audit logs are set to be cleared manually.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000139Not mappedCCI-001855Not mappedCCI-001858CCE-25110-8V-4108SV-52923

References

DPMS Target Microsoft Windows Server 2012-2012 R2 DC DISA DPMS Target Microsoft Windows Server 2012-2012 R2 DC 4217

Checks

OVAL

oval:mil.disa.fso.windows:var:457700 ← xccdf_mil.disa.stig_value_event_log_threshold_warning_var

DISA STIG (Manual Reference)

If the system is configured to write to an audit server, or is configured to automatically archive full logs, this is NA.

If the following registry value does not exist or is not configured as specified, this is a finding:

Registry Hive: HKEY_LOCAL_MACHINE 
Registry Path: \System\CurrentControlSet\Services\Eventlog\Security\

Value Name: WarningLevel

Value Type: REG_DWORD
Value: 90 (or less)

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

# Windows PowerShell
# Reconstructed from oval:mil.disa.fso.windows:def:4577
# The system must generate an audit event when the audit log reaches a percentage of full threshold.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Verifies 'MSS: (WarningLevel) Percentage threshold for the security event log at which the system will generate a warning' is set to 90 percent or less
# registry_object (registry_test)
function test_1 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security').GetValueKind('WarningLevel').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security' -Name 'WarningLevel' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'WarningLevel') -le 90))
}

if (test_1) {
  Write-Output "PASS"
} else {
  Write-Output "FAIL"
}

Assessment Script Powered by AISyntax-verified

A standalone PowerShell script to assess this control automatically. Review before running it in your environment.

Syntax-checked as valid PowerShell. Not executed here — running it for real needs the actual ms_windows_2012_and_2012_r2_dc target this check assesses.

# OVAL Definition: oval:mil.disa.fso.windows:def:4577
$threshold = 90
$registryPath = "HKLM:\SYSTEM\CurrentControlSet\Services\Eventlog\Security"
if (Test-Path $registryPath) {
    $regValue = (Get-ItemProperty -Path $registryPath -Name "WarningLevel").WarningLevel
    if ($regValue -le $threshold) {
        Write-Output "PASS"; exit 0
    }
}
Write-Output "FAIL"; exit 1

Remediation

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "MSS: (WarningLevel) Percentage threshold for the security event log at which the system will generate a warning" to "90" or less.

(See "Updating the Windows Security Options File" in the STIG Overview document if MSS settings are not visible in the system's policy tools.)