Zone information must be preserved when saving attachments.

STIG ID: WN11-UC-000020  |  SRG: SRG-OS-000480-GPOS-00227 |  Severity: medium (CAT II)  |  CCI: CCI-000366 |  Vulnerability Id: V-253478

Vulnerability Discussion

Preserving zone of origin (internet, intranet, local, restricted) information on file attachments allows Windows to determine risk.

Check

Note: This Check must be performed for each interactive user profile on the system.

The default behavior is for Windows to mark file attachments with their zone information.

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)

Note: This requirement is applicable to profiles for interactive logins. It is not applicable for Service accounts.

To determine the system's enabled user profiles:
Run "PowerShell" as an administrator.

Execute the following command:
Get-LocalUser | Where-Object {$_.Enabled -eq $true}

Fix

The default behavior is for Windows to mark file attachments with their zone information.

To correct this, (for each user profile on the system) 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".