SV-205756r958726: Windows Server 2019 Create symbolic links user right must only be assigned to the Administrators group. | Microsoft Windows Server 2019 STIG SCAP Benchmark

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Assessment Title

Rule Text

Windows Server 2019 Create symbolic links user right must only be assigned to the Administrators group.

Description

Discussion Text

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Create symbolic links" user right can create pointers to other objects, which could expose the system to attack.

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

IA Controls

NIST SP 800-53

Not mappedCCI-002235SV-103151V-93063

References

DPMS Target Microsoft Windows Server 2019 DISA DPMS Target Microsoft Windows Server 2019 2907

Checks

DISA STIG (Manual Reference)

Verify the effective setting in Local Group Policy Editor.

Run "gpedit.msc".

Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment.

If any accounts or groups other than the following are granted the "Create symbolic links" user right, this is a finding:

- Administrators

For server core installations, run the following command:

Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt

Review the text file.

If any SIDs other than the following are granted the "SeCreateSymbolicLinkPrivilege" user right, this is a finding:

S-1-5-32-544 (Administrators)

Systems that have the Hyper-V role will also have "Virtual Machines" given this user right (this may be displayed as "NT Virtual Machine\Virtual Machines", SID S-1-5-83-0). This is not a finding.

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.stig.windows2019:def:205756
# Windows Server 2019 Create symbolic links user right must only be assigned to the Administrators group.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Create symbolic links - Administrators
# userright_object (userright_test)
function test_1 {
  return ((($__tmp = "$env:TEMP\scc_userrights_$([guid]::NewGuid().Guid).cfg"; secedit /export /cfg $__tmp /areas USER_RIGHTS /quiet | Out-Null; $__m = Select-String -Path $__tmp -Pattern '^SeCreateSymbolicLinkPrivilege\s*=\s*(.*)$'; Remove-Item $__tmp -ErrorAction SilentlyContinue; if ($__m -and $__m.Matches[0].Groups[1].Value.Trim().Length -gt 0) { (($__m.Matches[0].Groups[1].Value -split ',') | ForEach-Object { $__sid = $_.Trim().TrimStart('*'); try { (New-Object System.Security.Principal.SecurityIdentifier($__sid)).Translate([System.Security.Principal.NTAccount]).Value -replace '^[^\\]*\\', '' } catch { $__sid } }) -join ',' } else { '' }) -eq '') -or (($__tmp = "$env:TEMP\scc_userrights_$([guid]::NewGuid().Guid).cfg"; secedit /export /cfg $__tmp /areas USER_RIGHTS /quiet | Out-Null; $__m = Select-String -Path $__tmp -Pattern '^SeCreateSymbolicLinkPrivilege\s*=\s*(.*)$'; Remove-Item $__tmp -ErrorAction SilentlyContinue; if ($__m -and $__m.Matches[0].Groups[1].Value.Trim().Length -gt 0) { (($__m.Matches[0].Groups[1].Value -split ',') | ForEach-Object { $__sid = $_.Trim().TrimStart('*'); try { (New-Object System.Security.Principal.SecurityIdentifier($__sid)).Translate([System.Security.Principal.NTAccount]).Value -replace '^[^\\]*\\', '' } catch { $__sid } }) -join ',' } else { '' }) -eq 'Administrators'))
}
# Create symbolic links - Administrators, Virtual Machines
# userright_object (userright_test)
function test_2 {
  return ((($__tmp = "$env:TEMP\scc_userrights_$([guid]::NewGuid().Guid).cfg"; secedit /export /cfg $__tmp /areas USER_RIGHTS /quiet | Out-Null; $__m = Select-String -Path $__tmp -Pattern '^SeCreateSymbolicLinkPrivilege\s*=\s*(.*)$'; Remove-Item $__tmp -ErrorAction SilentlyContinue; if ($__m -and $__m.Matches[0].Groups[1].Value.Trim().Length -gt 0) { (($__m.Matches[0].Groups[1].Value -split ',') | ForEach-Object { $__sid = $_.Trim().TrimStart('*'); try { (New-Object System.Security.Principal.SecurityIdentifier($__sid)).Translate([System.Security.Principal.NTAccount]).Value -replace '^[^\\]*\\', '' } catch { $__sid } }) -join ',' } else { '' }) -eq '') -or (($__tmp = "$env:TEMP\scc_userrights_$([guid]::NewGuid().Guid).cfg"; secedit /export /cfg $__tmp /areas USER_RIGHTS /quiet | Out-Null; $__m = Select-String -Path $__tmp -Pattern '^SeCreateSymbolicLinkPrivilege\s*=\s*(.*)$'; Remove-Item $__tmp -ErrorAction SilentlyContinue; if ($__m -and $__m.Matches[0].Groups[1].Value.Trim().Length -gt 0) { (($__m.Matches[0].Groups[1].Value -split ',') | ForEach-Object { $__sid = $_.Trim().TrimStart('*'); try { (New-Object System.Security.Principal.SecurityIdentifier($__sid)).Translate([System.Security.Principal.NTAccount]).Value -replace '^[^\\]*\\', '' } catch { $__sid } }) -join ',' } else { '' }) -eq 'Administrators') -or (($__tmp = "$env:TEMP\scc_userrights_$([guid]::NewGuid().Guid).cfg"; secedit /export /cfg $__tmp /areas USER_RIGHTS /quiet | Out-Null; $__m = Select-String -Path $__tmp -Pattern '^SeCreateSymbolicLinkPrivilege\s*=\s*(.*)$'; Remove-Item $__tmp -ErrorAction SilentlyContinue; if ($__m -and $__m.Matches[0].Groups[1].Value.Trim().Length -gt 0) { (($__m.Matches[0].Groups[1].Value -split ',') | ForEach-Object { $__sid = $_.Trim().TrimStart('*'); try { (New-Object System.Security.Principal.SecurityIdentifier($__sid)).Translate([System.Security.Principal.NTAccount]).Value -replace '^[^\\]*\\', '' } catch { $__sid } }) -join ',' } else { '' }) -match '^(?i)(NT VIRTUAL MACHINE\\)?Virtual Machines$'))
}
# Hyper-V Role is installed
# wmi57_object (wmi57_test)
function test_3 {
  return ($null -ne (Get-CimInstance -Namespace 'root\cimv2' -Query 'SELECT ID FROM Win32_ServerFeature'))
}

if ((test_1 -or (test_2 -and test_3))) {
  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_server_2019 target this check assesses.

# oval:mil.disa.stig.windows2019:def:205756
$createSymbolicLinkRight = Get-CimInstance -ClassName Win32_UserRight -Filter "UserRight = 'SE_CREATE_SYMBOLIC_LINK_NAME'"
if ($createSymbolicLinkRight -eq $null) {exit 0}
$admins = Get-CimInstance -ClassName Win32_UserRight -Filter "UserRight = 'SE_CREATE_SYMBOLIC_LINK_NAME' AND TrusteeName = 'Administrators'"
$vms = Get-CimInstance -ClassName Win32_UserRight -Filter "UserRight = 'SE_CREATE_SYMBOLIC_LINK_NAME' AND TrusteeName LIKE 'NT VIRTUAL MACHINE\\\\?Virtual Machines'"
if (($admins -ne $null) -and ($vms -eq $null -and (Get-CimInstance -ClassName Win32_HyperVRole).HyperVPresent -eq $false)) {exit 0}
exit 1

Remediation

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create symbolic links" to include only the following accounts or groups:

- Administrators

Systems that have the Hyper-V role will also have "Virtual Machines" given this user right. If this needs to be added manually, enter it as "NT Virtual Machine\Virtual Machines".