Ensure Direct Send submissions are rejected

中レベル 2手動レビューm365

説明

Direct Send is a method used to send emails directly to an Exchange Online customer’s hosted mailboxes from on-premises devices, applications, or third-party cloud services using the customer’s own accepted domain. This method does not require any form of authentication because, by its nature, it mimics incoming anonymous emails from the internet, apart from the sender domain. The recommended state is to configure RejectDirectSend to True. Direct Send allows devices and applications to transmit unauthenticated email directly to Exchange Online. While this method may support legacy systems such as printers or scanners, it introduces significant security risks: - Unauthenticated Email Delivery: Direct Send does not require authentication, making it an attractive vector for threat actors to deliver spoofed or malicious emails that appear to originate from trusted internal sources. - Phis...

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 PowerShell: 1. Connect to Exchange Online using Connect-ExchangeOnline. 2. Run the following PowerShell command: Get-OrganizationConfig | fl RejectDirectSend 3. Verify that the value returned for RejectDirectSend is True.

修正方法

修正方法: ガイダンスまたは IaC パッチ

To remediate using PowerShell: 1. Connect to Exchange Online using Connect-ExchangeOnline. 2. Run the following PowerShell command: Set-OrganizationConfig -RejectDirectSend $true

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 - 6.5.5 Ensure Direct Send submissions are rejected