Microsoft Exchange Server
TMA-EXCHANGE-2.3.4
Ensure 'Enable automatic forwards to remote domains' is set to 'False'
Description
This policy setting is used to determine if the server can send automatic forwards to remote domains. Prints the number of remote domains where AutoForwardEnabled is not False (expected 0). Automatic forwarding to external domains is a common exfiltration path. Every remote domain (including Default) is checked. Run on a Mailbox server (organization-wide objects are read from AD). Run from an Exchange Management Shell or after `Add-PSSnapin Microsoft.Exchange.Management.PowerShell.SnapIn`; the audit loads the snap-in itself when Get-ExchangeServer is missing and fails if it cannot.
How it is checked
Audit method: Shell command
$ErrorActionPreference = 'Stop'; if (-not (Get-Command Get-ExchangeServer -ErrorAction SilentlyContinue)) { Add-PSSnapin Microsoft.Exchange.Management.PowerShell.SnapIn -ErrorAction Stop }; if (-not (Get-Command Get-ExchangeServer -ErrorAction SilentlyContinue)) { throw 'Exchange Management Shell cmdlets are not available' }; $bad = @(Get-RemoteDomain -ErrorAction Stop | Where-Object { $_.AutoForwardEnabled -ne $false }); $bad.Count- Expected output
0
How it is fixed
Fix method: Guidance or infrastructure patch
Set-RemoteDomain '<RemoteDomain>' -AutoForwardEnabled $false
Properties
- Operating systems
- Any
- Tags
- exchangeremote-domains
- Reference
- CIS Microsoft Exchange Server 2019 Benchmark v1.0.1 - 2.3.4 Ensure 'Enable automatic forwards to remote domains' is set to 'False'
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target exchange