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

ÉlevéeNiveau 1Automatiséeoffice

Description

This policy setting allows controls whether Dynamic Data Exchange (DDE) server launch 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:disableddeserverlaunch (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.

Méthode de vérification

Méthode d'audit: Registre 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\' + $s + '\SOFTWARE\Policies\Microsoft\office\16.0\excel\security\externalcontent') -Name 'disableddeserverlaunch' -ErrorAction SilentlyContinue).'disableddeserverlaunch'; if (-not ($null -ne $v -and @(1) -contains [int64]$v)) { $bad += $s + ':disableddeserverlaunch=' + $v } }; if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') } }

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

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 launch in Excel = Enabled

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: officeproductivitycis-l1
Référence: CIS Microsoft Office Enterprise Benchmark v2.0.0 - 2.2.4.7.2.1.2 Ensure 'Don't allow Dynamic Data Exchange (DDE) server launch in Excel' is set to 'Enabled'

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target office