Permissions for system files and directories must conform to minimum requirements.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-63373	WN10-00-000095	SV-77863r1_rule		Medium

Description
Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications.

STIG	Date
Windows 10 Security Technical Implementation Guide	2017-02-21

Details

Check Text ( C-64115r1_chk )
The default file system permissions are adequate when the Security Option "Network access: Let Everyone permissions apply to anonymous users" is set to "Disabled" (WN10-SO-000160). If the default file system permissions are maintained and the referenced option is set to "Disabled", this is not a finding. Verify the default permissions for the sample directories below. 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.) Viewing in File Explorer: Select the "Security" tab, and the "Advanced" button. C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Administrators - Full control - This folder, subfolders and files SYSTEM - Full control - This folder, subfolders and files Users - Read & execute - This folder, subfolders and files Authenticated Users - Modify - Subfolders and files only Authenticated Users - Create folders / append data - This folder only \Program Files Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders and files \Windows Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders and files Alternately use icacls. Run "CMD" as administrator. Enter "icacls" followed by the directory. icacls c:\ icacls "c:\program files" icacls c:\windows The following results will be displayed as each is entered: c:\ BUILTIN\Administrators:(OI)(CI)(F) NT AUTHORITY\SYSTEM:(OI)(CI)(F) BUILTIN\Users:(OI)(CI)(RX) NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(M) NT AUTHORITY\Authenticated Users:(AD) Mandatory Label\High Mandatory Level:(OI)(NP)(IO)(NW) Successfully processed 1 files; Failed processing 0 files c:\program files NT SERVICE\TrustedInstaller:(F) NT SERVICE\TrustedInstaller:(CI)(IO)(F) NT AUTHORITY\SYSTEM:(M) NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F) BUILTIN\Administrators:(M) BUILTIN\Administrators:(OI)(CI)(IO)(F) BUILTIN\Users:(RX) BUILTIN\Users:(OI)(CI)(IO)(GR,GE) CREATOR OWNER:(OI)(CI)(IO)(F) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) Successfully processed 1 files; Failed processing 0 files c:\windows NT SERVICE\TrustedInstaller:(F) NT SERVICE\TrustedInstaller:(CI)(IO)(F) NT AUTHORITY\SYSTEM:(M) NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F) BUILTIN\Administrators:(M) BUILTIN\Administrators:(OI)(CI)(IO)(F) BUILTIN\Users:(RX) BUILTIN\Users:(OI)(CI)(IO)(GR,GE) CREATOR OWNER:(OI)(CI)(IO)(F) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) Successfully processed 1 files; Failed processing 0 files

Check Text ( C-64115r1_chk )

The default file system permissions are adequate when the Security Option "Network access: Let Everyone permissions apply to anonymous users" is set to "Disabled" (WN10-SO-000160).

If the default file system permissions are maintained and the referenced option is set to "Disabled", this is not a finding.

Verify the default permissions for the sample directories below. 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.)

Viewing in File Explorer:
Select the "Security" tab, and the "Advanced" button.

C:\
Type - "Allow" for all
Inherited from - "None" for all
Principal - Access - Applies to
Administrators - Full control - This folder, subfolders and files
SYSTEM - Full control - This folder, subfolders and files
Users - Read & execute - This folder, subfolders and files
Authenticated Users - Modify - Subfolders and files only
Authenticated Users - Create folders / append data - This folder only

\Program Files
Type - "Allow" for all
Inherited from - "None" for all
Principal - Access - Applies to
TrustedInstaller - Full control - This folder and subfolders
SYSTEM - Modify - This folder only
SYSTEM - Full control - Subfolders and files only
Administrators - Modify - This folder only
Administrators - Full control - Subfolders and files only
Users - Read & execute - This folder, subfolders and files
CREATOR OWNER - Full control - Subfolders and files only
ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders and files

\Windows
Type - "Allow" for all
Inherited from - "None" for all
Principal - Access - Applies to
TrustedInstaller - Full control - This folder and subfolders
SYSTEM - Modify - This folder only
SYSTEM - Full control - Subfolders and files only
Administrators - Modify - This folder only
Administrators - Full control - Subfolders and files only
Users - Read & execute - This folder, subfolders and files
CREATOR OWNER - Full control - Subfolders and files only
ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders and files

Alternately use icacls.

Run "CMD" as administrator.
Enter "icacls" followed by the directory.

icacls c:\
icacls "c:\program files"
icacls c:\windows

The following results will be displayed as each is entered:

c:\
BUILTIN\Administrators:(OI)(CI)(F)
NT AUTHORITY\SYSTEM:(OI)(CI)(F)
BUILTIN\Users:(OI)(CI)(RX)
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(M)
NT AUTHORITY\Authenticated Users:(AD)
Mandatory Label\High Mandatory Level:(OI)(NP)(IO)(NW)
Successfully processed 1 files; Failed processing 0 files

c:\program files
NT SERVICE\TrustedInstaller:(F)
NT SERVICE\TrustedInstaller:(CI)(IO)(F)
NT AUTHORITY\SYSTEM:(M)
NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F)
BUILTIN\Administrators:(M)
BUILTIN\Administrators:(OI)(CI)(IO)(F)
BUILTIN\Users:(RX)
BUILTIN\Users:(OI)(CI)(IO)(GR,GE)
CREATOR OWNER:(OI)(CI)(IO)(F)
APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX)
APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE)
Successfully processed 1 files; Failed processing 0 files

c:\windows
NT SERVICE\TrustedInstaller:(F)
NT SERVICE\TrustedInstaller:(CI)(IO)(F)
NT AUTHORITY\SYSTEM:(M)
NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F)
BUILTIN\Administrators:(M)
BUILTIN\Administrators:(OI)(CI)(IO)(F)
BUILTIN\Users:(RX)
BUILTIN\Users:(OI)(CI)(IO)(GR,GE)
CREATOR OWNER:(OI)(CI)(IO)(F)
APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX)
APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE)
Successfully processed 1 files; Failed processing 0 files

Fix Text (F-69295r1_fix)
Maintain the default file system permissions and configure the Security Option: "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (WN10-SO-000160).