Windows Server 2019 must preserve zone information when saving attachments.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-205924	WN19-UC-000010	SV-205924r569188_rule		Medium

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.

STIG	Date
Microsoft Windows Server 2019 Security Technical Implementation Guide	2020-10-26

Details

Check Text ( C-6189r356134_chk )
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)

Check Text ( C-6189r356134_chk )

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 Text (F-6189r356135_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".