SV-224970r958726: Permissions on the Active Directory data files must only allow System and Administrators access. | Microsoft Windows Server 2016 STIG SCAP Benchmark

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Assessment Title

Rule Text

Permissions on the Active Directory data files must only allow System and Administrators access.

Description

Discussion Text

Improper access permissions for directory data-related files could allow unauthorized users to read, modify, or delete directory data or audit trails.

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

IA Controls

NIST SP 800-53

Not mappedCCI-002235SV-88021V-73369

References

DPMS Target Microsoft Windows Server 2016 DISA DPMS Target Microsoft Windows Server 2016 4205

Checks

DISA STIG (Manual Reference)

This applies to domain controllers. It is NA for other systems.

Run "Regedit".

Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters".

Note the directory locations in the values for:

Database log files path
DSA Database file

By default, they will be \Windows\NTDS.

If the locations are different, the following will need to be run for each.

Open "Command Prompt (Admin)".

Navigate to the NTDS directory (\Windows\NTDS by default).

Run "icacls *.*".

If the permissions on each file are not as restrictive as the following, this is a finding.

NT AUTHORITY\SYSTEM:(I)(F)
BUILTIN\Administrators:(I)(F)

(I) - permission inherited from parent container
(F) - full access

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.

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_server_2016 target this check assesses.

# OVAL Definition: oval:mil.disa.stig.windows2016:def:224970
$ntdsPath = (Get-ItemProperty -Path 'HKLM:\System\CurrentControlSet\Services\NTDS\Parameters' -Name 'Database log files path' -ErrorAction SilentlyContinue).GetValue('Database log files path')
if ($ntdsPath) {
    $requiredRights = @{
        "file_write_data" = $true
        "file_delete_child" = $true
        "file_write_ea" = $true
        "file_read_ea" = $true
        "file_read_attributes" = $true
        "generic_read" = $true
        "file_execute" = $true
        "generic_execute" = $true
        "standard_delete" = $true
        "file_read_data" = $true
        "file_append_data" = $true
        "standard_synchronize" = $true
        "standard_write_owner" = $true
        "standard_read_control" = $true
        "file_write_attributes" = $true
        "standard_write_dac" = $true
        "generic_write" = $true
    }
    $users = @("NT AUTHORITY\SYSTEM", "BUILTIN\Administrators")
    foreach ($user in $users) {
        $sid = (New-Object System.Security.Principal.SecurityIdentifier($user)).Value
        foreach ($file in Get-ChildItem -Path $ntdsPath -Recurse -File) {
            $acl = Get-Acl -Path $file.FullName
            $accessRule = $acl.Access | Where-Object {$_.IdentityReference.Value -eq $sid}
            if ($accessRule -eq $null -or $requiredRights.GetEnumerator().ForEach({$accessRule.IsInherited -eq $_.Key -and $accessRule.FileSystemRights -contains $_.Value}).Contains($false)) {
                Write-Output "FAIL"
                exit 1
            }
        }
    }
}
Write-Output "PASS"
exit 0

Remediation

Maintain the permissions on NTDS database and log files as follows:

NT AUTHORITY\SYSTEM:(I)(F)
BUILTIN\Administrators:(I)(F)

(I) - permission inherited from parent container
(F) - full access