Windows Server 2019 must preserve zone information when saving attachments.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-205924	SRG-OS-000480-GPOS-00227	WN19-UC-000010	SV-205924r991589_rule	2025-02-25	3

Description
Attachments from outside sources may contain malicious code. Preserving zone of origin (Internet, intranet, local, restricted) information on file attachments allows Windows to determine risk.

ℹ️ Check
The default behavior is for Windows to mark file attachments with their zone information. If the registry Value Name below does not exist, this is not a finding. If it exists and is configured with a value of "2", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_CURRENT_USER Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments\ Value Name: SaveZoneInformation Value Type: REG_DWORD Value: 0x00000002 (2) (or if the Value Name does not exist)

ℹ️ Check

The default behavior is for Windows to mark file attachments with their zone information. If the registry Value Name below does not exist, this is not a finding. If it exists and is configured with a value of "2", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_CURRENT_USER Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments\ Value Name: SaveZoneInformation Value Type: REG_DWORD Value: 0x00000002 (2) (or if the Value Name does not exist)

✔️ Fix
The default behavior is for Windows to mark file attachments with their zone information. If this needs to be corrected, configure the policy value for User Configuration >> Administrative Templates >> Windows Components >> Attachment Manager >> "Do not preserve zone information in file attachments" to "Not Configured" or "Disabled".