Windows Server 2019 data files owned by users must be on a different logical partition from the directory server data files.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-205723	SRG-OS-000138-GPOS-00069	WN19-DC-000120	SV-205723r958524_rule	2025-02-25	3

Description
When directory service data files, especially for directories used for identification, authentication, or authorization, reside on the same logical partition as user-owned files, the directory service data may be more vulnerable to unauthorized access or other availability compromises. Directory service and user-owned data files sharing a partition may be configured with less restrictive permissions in order to allow access to the user data. The directory service may be vulnerable to a denial of service attack when user-owned files on a common partition are expanded to an extent preventing the directory service from acquiring more space for directory or audit data.

Description

When directory service data files, especially for directories used for identification, authentication, or authorization, reside on the same logical partition as user-owned files, the directory service data may be more vulnerable to unauthorized access or other availability compromises. Directory service and user-owned data files sharing a partition may be configured with less restrictive permissions in order to allow access to the user data. The directory service may be vulnerable to a denial of service attack when user-owned files on a common partition are expanded to an extent preventing the directory service from acquiring more space for directory or audit data.

ℹ️ Check
This applies to domain controllers. It is NA for other systems. Run "Regedit". Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters". Note the directory locations in the values for "DSA Database file". Open "Command Prompt". Enter "net share". Note the logical drive(s) or file system partition for any organization-created data shares. Ignore system shares (e.g., NETLOGON, SYSVOL, and administrative shares ending in $). User shares that are hidden (ending with $) should not be ignored. If user shares are located on the same logical partition as the directory server data files, this is a finding.

ℹ️ Check

This applies to domain controllers. It is NA for other systems. Run "Regedit". Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters". Note the directory locations in the values for "DSA Database file". Open "Command Prompt". Enter "net share". Note the logical drive(s) or file system partition for any organization-created data shares. Ignore system shares (e.g., NETLOGON, SYSVOL, and administrative shares ending in $). User shares that are hidden (ending with $) should not be ignored. If user shares are located on the same logical partition as the directory server data files, this is a finding.

✔️ Fix
Move shares used to store files owned by users to a different logical partition than the directory server data files.