Ensure that collaboration invitations are sent to allowed domains only

低レベル 2手動レビューm365

説明

B2B collaboration is a feature within Microsoft Entra External ID that allows for guest invitations to an organization. Ensure users can only send invitations to specified domains. Note: This list works independently from OneDrive for Business and SharePoint Online allow/block lists. To restrict individual file sharing in SharePoint Online, set up an allow or blocklist for OneDrive for Business and SharePoint Online. For instance, in SharePoint or OneDrive users can still share with external users from prohibited domains by using Anyone links if they haven't been disabled. By specifying allowed domains for collaborations, external user's companies are explicitly identified. Also, this prevents internal users from inviting unknown external users such as personal accounts and granting them access to resources.

チェック方法

監査方法: 手動レビュー

この推奨事項は自動ではチェックできません。--include-manual を指定すると、スキャン結果にこの手順付きで一覧表示されます。

To audit using the UI: 1. Navigate to Microsoft Entra admin center https://entra.microsoft.com/. 2. Expand Entra ID > External Identities and select External collaboration settings. 3. Under Collaboration restrictions, verify that Allow invitations only to the specified domains (most restrictive) is selected. Then verify allowed domains are specified under Target domains. To audit using PowerShell: 1. Connect to Microsoft Graph using Connect-MgGraph -Scopes "Policy.Read.All" 2. Run the following: $Uri = "https://graph.microsoft.com/beta/legacy/policies" $Response = (Invoke-MgGraphRequest -Uri $Uri).value | Where-Object { $_.type -eq 'B2BManagementPolicy' } if ($Response) { $Definition = $Response.definition | ConvertFrom-Json $DomainsPolicy = $Definition.B2BManagementPolicy.InvitationsAllowedAndBlockedDomainsPolicy } else { Write-Output "No policy found." return } $DomainsPolicy 3. Verify that the output includes an AllowedDomains property that either contains no domains or lists only organizationally approved domains. If a BlockedDomains property is present, the configuration is considered non-compliant. Example of a compliant output with AllowedDomains defined: AllowedDomains...

修正方法

修正方法: ガイダンスまたは IaC パッチ

To remediate using the UI: 1. Navigate to Microsoft Entra admin center https://entra.microsoft.com/. 2. Expand Entra ID > External Identities and select External collaboration settings. 3. Under Collaboration restrictions, select Allow invitations only to the specified domains (most restrictive) is selected. Then specify the allowed domains under Target domains.

プロパティ

オペレーティングシステム: すべて
タグ: m365saas
参照: CIS Microsoft 365 Foundations Benchmark v7.0.0 - 5.1.6.1 Ensure that collaboration invitations are sent to allowed domains only