Unsupported IBM z/OS system software must not be installed and/or active on the system.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223561	ACF2-OS-000250	SV-223561r533198_rule		High

Description
Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles).

Description

Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles).

STIG	Date
IBM z/OS ACF2 Security Technical Implementation Guide	2021-03-29

Details

Check Text ( C-25234r504710_chk )
This check applies to all products that meet the following criteria: - Uses authorized and restricted z/OS interfaces by utilizing Authorized Program Facility (APF) authorized modules or libraries. - Require access to system data sets or sensitive information or requires special or privileged authority to run. For the products in the above category refer to the Vendor’s support lifecycle information for current versions and releases. If the software products currently running on the reviewed system are at a version greater than or equal to the products listed in the vendor’s Support Lifecycle information, this is not a finding.

Check Text ( C-25234r504710_chk )

This check applies to all products that meet the following criteria:

- Uses authorized and restricted z/OS interfaces by utilizing Authorized Program Facility (APF) authorized modules or libraries.
- Require access to system data sets or sensitive information or requires special or privileged authority to run.

For the products in the above category refer to the Vendor’s support lifecycle information for current versions and releases.

If the software products currently running on the reviewed system are at a version greater than or equal to the products listed in the vendor’s Support Lifecycle information, this is not a finding.

Fix Text (F-25222r504711_fix)
For all products that meet the following criteria: - Uses authorized and restricted z/OS interfaces by utilizing Authorized Program Facility (APF) authorized modules or libraries. - Require access to system data sets or sensitive information or requires special or privileged authority to run. The ISSO will ensure that unsupported system software for the products in the above category is removed or upgraded prior to a vendor dropping support. Authorized software which is NO longer supported is a CAT I – vulnerability. The customer and site will be given 6 months to mitigate the risk, come up with a supported solution or obtain a formal letter approving such risk/software.

Fix Text (F-25222r504711_fix)

For all products that meet the following criteria:

- Uses authorized and restricted z/OS interfaces by utilizing Authorized Program Facility (APF) authorized modules or libraries.
- Require access to system data sets or sensitive information or requires special or privileged authority to run.

The ISSO will ensure that unsupported system software for the products in the above category is removed or upgraded prior to a vendor dropping support.

Authorized software which is NO longer supported is a CAT I – vulnerability. The customer and site will be given 6 months to mitigate the risk, come up with a supported solution or obtain a formal letter approving such risk/software.