Permissions for the system drive root directory (usually C:\) must conform to minimum requirements.

From Windows Server 2016 Security Technical Implementation Guide

Part of SRG-OS-000312-GPOS-00122

Associated with: CCI-002165

SV-87901r1_rule Permissions for the system drive root directory (usually C:\) must conform to minimum requirements.

Vulnerability discussion

Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications.The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290).Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124

Check content

The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Review the permissions for the system drive's root directory (usually C:\). Non-privileged groups such as Users or Authenticated Users must not have greater than "Read & execute" permissions except where noted as defaults. (Individual accounts must not be used to assign permissions.) If permissions are not as restrictive as the default permissions listed below, this is a finding. Viewing in File Explorer: View the Properties of the system drive's root directory. Select the "Security" tab, and the "Advanced" button. Default permissions: C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full control - This folder, subfolders, and files Administrators - Full control - This folder, subfolders, and files Users - Read & execute - This folder, subfolders, and files Users - Create folders/append data - This folder and subfolders Users - Create files/write data - Subfolders only CREATOR OWNER - Full Control - Subfolders and files only Alternately, use icacls: Open "Command Prompt (Admin)". Enter "icacls" followed by the directory: "icacls c:\" The following results should be displayed: c:\ NT AUTHORITY\SYSTEM:(OI)(CI)(F) BUILTIN\Administrators:(OI)(CI)(F) BUILTIN\Users:(OI)(CI)(RX) BUILTIN\Users:(CI)(AD) BUILTIN\Users:(CI)(IO)(WD) CREATOR OWNER:(OI)(CI)(IO)(F) Successfully processed 1 files; Failed processing 0 files

Fix text

Maintain the default permissions for the system drive's root directory and configure the Security Option "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (WN16-SO-000290). Default Permissions C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full control - This folder, subfolders, and files Administrators - Full control - This folder, subfolders, and files Users - Read & execute - This folder, subfolders, and files Users - Create folders/append data - This folder and subfolders Users - Create files/write data - Subfolders only CREATOR OWNER - Full Control - Subfolders and files only

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.

Powered by sagemincer