1.1.1.2.1.34 Set 'System settings: Optional subsystems' to ''

Information

This policy setting determines which subsystems are used to support applications in your environment. Note: When you configure this setting you specify a list of one or more objects. The delimiter used when entering the list is a line feed or carriage return, that is, type the first object on the list, press the Enter button, type the next object, press Enter again, etc. The setting value is stored as a comma-delimited list in group policy security templates. It is also rendered as a comma-delimited list in Group Policy Editor's display pane and the Resultant Set of Policy console. It is recorded in the registry as a line-feed delimited list in a REG_MULTI_SZ value. The POSIX subsystem is an Institute of Electrical and Electronic Engineers (IEEE) standard that defines a set of operating system services. The POSIX subsystem is required if the server supports applications that use that subsystem. The POSIX subsystem introduces a security risk that relates to processes that can potentially persist across logons. If a user starts a process and then logs out, there is a potential that the next user who logs on to the computer could access the previous user's process. This potential is dangerous, because anything the second user does with that process will be performed with the privileges of the first user.

Solution

To implement the recommended configuration state, set the following Group Policy setting to .

Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\System settings- Optional subsystems

Impact- Applications that rely on the POSIX subsystem will no longer operate. For example, Microsoft Services for Unix (SFU) installs an updated version of the POSIX subsystem that is required, so you would need to reconfigure this setting in a Group Policy for any servers that use SFU.

See Also

https://workbench.cisecurity.org/files/42

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-7, CCE|CCE-17448-2, CSCv6|9.1

Plugin: Windows

Control ID: f127f9f22fed1d7e8234f955c7114f1ca691399b23ee20a3e5ac060b1d91e776