Ensure 'Don't allow Dynamic Data Exchange (DDE) server lookup in Excel' is set to 'Enabled'

TinggiLevel 1Otomatisoffice

Deskripsi

This policy setting allows controls whether Dynamic Data Exchange (DDE) server lookup is allowed. The DDE protocol is a set of messages and guidelines. It sends messages between applications that share data and uses shared memory to exchange data between applications. Rationale: In an email attack scenario, an attacker could leverage the DDE protocol by sending a specially crafted file to the user and then convincing the user to open the file, typically by way of an enticement in an email. User setting: the audit checks HKEY_USERS\<SID>\SOFTWARE\Policies\Microsoft\office\16.0\excel\security\externalcontent:disableddeserverlookup (REG_DWORD) in every loaded user hive (S-1-5-21-*) and is compliant when each holds 1. It prints 'no-user-hive-loaded' (FAIL) when no user profile is loaded, so scan while users are logged on.

Cara pemeriksaan

Metode audit: Registry Windows

registry

$sids = @(Get-ChildItem -Path 'Registry::HKEY_USERS' -ErrorAction SilentlyContinue | Where-Object { $_.PSChildName -match '^S-1-5-21-\d+-\d+-\d+-\d+$' } | ForEach-Object { $_.PSChildName }); if ($sids.Count -eq 0) { 'no-user-hive-loaded' } else { $bad = @(); foreach ($s in $sids) { $v = (Get-ItemProperty -Path ('Registry::HKEY_USERS\' + $s + '\SOFTWARE\Policies\Microsoft\office\16.0\excel\security\externalcontent') -Name 'disableddeserverlookup' -ErrorAction SilentlyContinue).'disableddeserverlookup'; if (-not ($null -ne $v -and @(1) -contains [int64]$v)) { $bad += $s + ':disableddeserverlookup=' + $v } }; if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') } }

Output yang diharapkan: compliant

Cara perbaikan

Metode perbaikan: Panduan atau patch infrastruktur

Configure through Group Policy (User Configuration): User Configuration\Administrative Templates\Microsoft Excel 2016\Excel Options\Security\Trust Center\External Content\Don’t allow Dynamic Data Exchange (DDE) server lookup in Excel = Enabled

Properti

Sistem operasi: Apa saja
Tag: officeproductivitycis-l1
Referensi: CIS Microsoft Office Enterprise Benchmark v2.0.0 - 2.2.4.7.2.1.3 Ensure 'Don't allow Dynamic Data Exchange (DDE) server lookup in Excel' is set to 'Enabled'

Periksa host ini

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shell

tmaegis scan --target office