Ensure 'External sharing' of calendars is not available

低レベル 2手動レビューm365

説明

External calendar sharing allows an administrator to enable the ability for users to share calendars with anyone outside of the organization. Outside users will be sent a URL that can be used to view the calendar. Attackers often spend time learning about organizations before launching an attack. Publicly available calendars can help attackers understand organizational relationships and determine when specific users may be more vulnerable to an attack, such as when they are traveling.

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 365 admin center https://admin.microsoft.com. 2. Expand Settings > Org settings. 3. In the Services section click Calendar. 4. Verify that Let your users share their calendars with people outside of your organization who have Office 365 or Exchange is unchecked. To audit using PowerShell: 1. Connect to Exchange Online using Connect-ExchangeOnline. 2. Run the following Exchange Online PowerShell command: Get-SharingPolicy -Identity "Default Sharing Policy" | ft Name,Enabled 3. Verify that Enabled is set to False

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 365 admin center https://admin.microsoft.com. 2. Expand Settings select Org settings. 3. In the Services section click Calendar. 4. Uncheck Let your users share their calendars with people outside of your organization who have Office 365 or Exchange. 5. Click Save. To remediate using PowerShell: 1. Connect to Exchange Online using Connect-ExchangeOnline. 2. Run the following Exchange Online PowerShell command: Set-SharingPolicy -Identity "Default Sharing Policy" -Enabled $False

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 - 1.3.3 Ensure 'External sharing' of calendars is not available