Visio: Disable Network Trusted Locations

πŸ’Ό Management Samenvatting

Disable network trusted locations in Visio - prevents UNC path trusted folders (network share macro bypass).

Aanbeveling
IMPLEMENT
Risico zonder
High
Risk Score
8/10
Implementatie
2u (tech: 1u)
Van toepassing op:
βœ“ Microsoft Visio

Network trusted locations = security bypass: Trusted locations: Folders where macros ALWAYS run (no security checks), Network paths: UNC paths (\\server\share\visio-templates) as trusted location, Attack: Compromised network share β†’ attacker places malicious .vsdm file in trusted UNC path β†’ macros auto-run (bypass ALL security), Lateral movement: Attacker compromises file share β†’ instant macro execution on all users accessing trusted share. Network shares = weak trust boundary (many users have write access). Block network trusted: ONLY local paths allowed as trusted (C:\Trusted - admin-controlled), Network paths: BLOCKED (cannot be trusted locations).

PowerShell Modules Vereist
Primary API: Intune / GPO
Connection: Registry-based
Required Modules:

Implementatie

Block network trusted: Policy: Disable all trusted locations on the network: Enabled, Effect: Network UNC paths CANNOT be trusted locations (macro security applies), Local trusted: Still allowed (C:\ paths - if needed), SharePoint: NOT affected (HTTPS, not UNC - separate trust model).

Vereisten

  1. Visio 2016+
  2. Intune of GPO

Implementatie

Intune Settings Catalog: Visio\Security\Trust Center\Trusted Locations β†’ Allow Trusted Locations on the network: Disabled (block network trusted).

Compliance

CIS Office Benchmark L1, BIO 12.02, Microsoft Security Baseline.

Monitoring

Gebruik PowerShell-script network-trusted-locations-disabled.ps1 (functie Invoke-Monitoring) – Controleren.

Remediatie

Gebruik PowerShell-script network-trusted-locations-disabled.ps1 (functie Invoke-Remediation) – Herstellen.

Compliance & Frameworks

Automation

Gebruik het onderstaande PowerShell script om deze security control te monitoren en te implementeren. Het script bevat functies voor zowel monitoring (-Monitoring) als remediation (-Remediation).

PowerShell
<# .SYNOPSIS Schakelt vertrouwde netwerk locaties uit in Visio .DESCRIPTION Dit script implementeert CIS control O365-VI-000002 voor het uitschakelen van vertrouwde netwerk locaties in Microsoft Visio. Dit voorkomt dat bestanden van netwerk locaties automatisch als vertrouwd worden behandeld, wat een beveiligingsrisico kan vormen. .REQUIREMENTS - PowerShell 5.1 of hoger - Lokale administrator rechten voor registry wijzigingen - Microsoft Visio geΓ―nstalleerd .PARAMETER Monitoring Controleert de huidige compliance status .PARAMETER Remediation Past de aanbevolen configuratie toe .PARAMETER Revert Herstelt de originele configuratie .PARAMETER WhatIf Toont wat er zou gebeuren zonder wijzigingen door te voeren .EXAMPLE .\network-trusted-locations-disabled.ps1 -Monitoring Controleert of netwerk vertrouwde locaties zijn uitgeschakeld .EXAMPLE .\network-trusted-locations-disabled.ps1 -Remediation Schakelt netwerk vertrouwde locaties uit .NOTES Registry pad: HKCU:\Software\Policies\Microsoft\Office\16.0\Visio\Security\Trusted Locations Waarde: AllowNetworkLocations = 0 CIS Control: O365-VI-000002 #> #Requires -Version 5.1 param( [switch]$Monitoring, [switch]$Remediation, [switch]$Revert, [switch]$WhatIf ) # Globale variabelen $RegistryPath = "HKCU:\Software\Policies\Microsoft\Office\16.0\Visio\Security\Trusted Locations" $ValueName = "AllowNetworkLocations" $ExpectedValue = 0 $ControlID = "O365-VI-000002" function Test-Compliance { try { if (-not (Test-Path $RegistryPath)) { return $false } $currentValue = Get-ItemProperty -Path $RegistryPath -Name $ValueName -ErrorAction SilentlyContinue return ($currentValue -and $currentValue.$ValueName -eq $ExpectedValue) } catch { return $false } } function Invoke-Monitoring { Write-Host "Monitoring ${ControlID}: Netwerk vertrouwde locaties uitschakelen" -ForegroundColor Green try { if (-not (Test-Path $RegistryPath)) { Write-Host "βœ— Registry pad bestaat niet: $RegistryPath" -ForegroundColor Red return $false } $currentValue = Get-ItemProperty -Path $RegistryPath -Name $ValueName -ErrorAction SilentlyContinue if ($currentValue -and $currentValue.$ValueName -eq $ExpectedValue) { Write-Host "βœ“ Control compliant: ${ValueName} = $ExpectedValue" -ForegroundColor Green return $true } else { $actualValue = if ($currentValue) { $currentValue.$ValueName } else { "Not Set" } Write-Host "βœ— Control non-compliant: ${ValueName} = $actualValue (Expected: $ExpectedValue)" -ForegroundColor Red return $false } } catch { Write-Host "βœ— Fout bij controleren registry instelling: $($_.Exception.Message)" -ForegroundColor Red return $false } } function Invoke-Remediation { Write-Host "Remediating ${ControlID}: Netwerk vertrouwde locaties uitschakelen" -ForegroundColor Yellow try { if ($WhatIf) { Write-Host "WhatIf: Zou registry waarde instellen: ${ValueName} = $ExpectedValue" -ForegroundColor Cyan return $true } if (-not (Test-Path $RegistryPath)) { Write-Host "Registry pad aanmaken: $RegistryPath" -ForegroundColor Yellow New-Item -Path $RegistryPath -Force | Out-Null } Set-ItemProperty -Path $RegistryPath -Name $ValueName -Value $ExpectedValue -Type DWord -Force Write-Host "βœ“ Registry waarde succesvol ingesteld: ${ValueName} = $ExpectedValue" -ForegroundColor Green Start-Sleep -Seconds 1 return Invoke-Monitoring } catch { Write-Host "βœ— Fout bij configureren registry instelling: $($_.Exception.Message)" -ForegroundColor Red return $false } } function Invoke-Revert { Write-Host "Reverting ${ControlID}: Netwerk vertrouwde locaties instelling herstellen" -ForegroundColor Yellow try { if ($WhatIf) { Write-Host "WhatIf: Zou registry waarde verwijderen: ${ValueName}" -ForegroundColor Cyan return $true } if (Test-Path $RegistryPath) { Remove-ItemProperty -Path $RegistryPath -Name $ValueName -ErrorAction SilentlyContinue Write-Host "βœ“ Registry waarde verwijderd: ${ValueName}" -ForegroundColor Green } return $true } catch { Write-Host "βœ— Fout bij herstellen registry instelling: $($_.Exception.Message)" -ForegroundColor Red return $false } } # Hoofd uitvoering try { if ($Monitoring) { $result = Invoke-Monitoring exit $(if ($result) { 0 } else { 1 }) } elseif ($Remediation) { $result = Invoke-Remediation exit $(if ($result) { 0 } else { 1 }) } elseif ($Revert) { $result = Invoke-Revert exit $(if ($result) { 0 } else { 1 }) } else { Write-Host "Gebruik: .\network-trusted-locations-disabled.ps1 [-Monitoring] [-Remediation] [-Revert] [-WhatIf]" -ForegroundColor Yellow Write-Host " -Monitoring: Controleer huidige compliance status" -ForegroundColor White Write-Host " -Remediation: Pas aanbevolen configuratie toe" -ForegroundColor White Write-Host " -Revert: Herstel originele configuratie" -ForegroundColor White Write-Host " -WhatIf: Toon wat er zou gebeuren" -ForegroundColor White } } catch { Write-Host "βœ— Onverwachte fout: $($_.Exception.Message)" -ForegroundColor Red exit 1 }

Risico zonder implementatie

Risico zonder implementatie
High: Hoog: Network trusted locations = compromised share β†’ instant macro execution (bypass security).

Management Samenvatting

Disable Visio network trusted locations. UNC paths cannot bypass macro security. Local trusted: OK. Implementatie: 1-2 uur.