A Windows system has a writable DCOM configuration.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-6826	5.108	SV-29543r1_rule		Medium

Description
A registry key for a valid DCOM object has access permissions that could allow non-administrator users to change the security settings if inadvertently set to a low level of security. An attacker could possibly execute code under the context of the console or some other user.

STIG	Date
Windows Vista Security Technical Implementation Guide	2017-01-30

Details

Check Text ( C-39216r1_chk )
Verify the permissions of the following registry key and its subkeys: HKLM\Software\Classes\Appid If any standard (non-privileged) user accounts or groups have greater than “read” access, then this would be a finding. The default permissions are acceptable. At the Appid level they are as follows and will be inherited by many of the subkeys. Creator Owner - Special (Full) Administrators - Full SYSTEM - Full Users - Read Vista subkeys that have Trusted Installer with “Full” permissions are acceptable. These will typically have lesser permissions of "Read" for Administrators and System.

Check Text ( C-39216r1_chk )

Verify the permissions of the following registry key and its subkeys:

HKLM\Software\Classes\Appid

If any standard (non-privileged) user accounts or groups have greater than “read” access, then this would be a finding.

The default permissions are acceptable. At the Appid level they are as follows and will be inherited by many of the subkeys.

Creator Owner - Special (Full)
Administrators - Full
SYSTEM - Full
Users - Read

Vista subkeys that have Trusted Installer with “Full” permissions are acceptable. These will typically have lesser permissions of "Read" for Administrators and System.

Fix Text (F-6513r1_fix)
Fortify DCOMs AppId permissions. Any changes should be thoroughly tested so objects continue to function under tightened security. - Open the Registry Editor. - Navigate to HKEY_LOCAL_MACHINE\Software\Classes\Appid. - Select the application that generated this vulnerability. - Set the permissions for standard (non-privileged) user accounts or groups to Read only.