z/OS UNIX SUPERUSER resource must be protected in accordance with guidelines.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-6972	ZUSS0023	SV-19749r3_rule		High

Description
z/OS UNIX ACP-defined resources consist of sensitive capabilities including SUPERUSER, daemon, and numerous file manipulation privileges. Missing or inaccurate protection of these resources could allow a user to access sensitive data, modify or delete data and operating system controls, or issue commands that could negatively impact system availability.

STIG	Date
z/OS TSS STIG	2019-12-12

Details

Check Text ( C-20445r1_chk )
a) Refer to the following reports produced by the TSS Data Collection and Data Set and Resource Data Collection: - TSSCMDS.RPT(WHOOUNI) - SENSITVE.RPT(WHOHUNI) Automated Analysis Refer to the following report produced by the Data Set and Resource Data Collection: - PDI(ZUSS0023) b) Review the following items for the UNIXPRIV resource class: 1) The TSS owner defined for the SUPERUSER resource. 2) There are no TSS rules that allow access to the SUPERUSER resource. 3) There is no TSS rule for CHOWN.UNRESTRICTED defined. 4) The TSS rules for each of the SUPERUSER resources listed in the UNIXPRIV CLASS RESOURCES Table in the z/OS STIG Addendum, restrict access to appropriate system tasks or systems programming personnel. c) If any item in (b) is untrue, this is a FINDING. d) If all items in (b) are true, this is NOT A FINDING.

Check Text ( C-20445r1_chk )

a) Refer to the following reports produced by the TSS Data Collection and Data Set and Resource Data Collection:

- TSSCMDS.RPT(WHOOUNI)
- SENSITVE.RPT(WHOHUNI)

Automated Analysis
Refer to the following report produced by the Data Set and Resource Data Collection:

- PDI(ZUSS0023)

b) Review the following items for the UNIXPRIV resource class:

1) The TSS owner defined for the SUPERUSER resource.
2) There are no TSS rules that allow access to the SUPERUSER resource.
3) There is no TSS rule for CHOWN.UNRESTRICTED defined.
4) The TSS rules for each of the SUPERUSER resources listed in the UNIXPRIV CLASS RESOURCES Table in the z/OS STIG Addendum, restrict access to appropriate system tasks or systems programming personnel.

c) If any item in (b) is untrue, this is a FINDING.

d) If all items in (b) are true, this is NOT A FINDING.

Fix Text (F-19110r1_fix)
The IAO will ensure that all SUPERUSER resources for the UNIXPRIV resource class are restricted to appropriate system tasks and/or system programming personnel. Review the following items for the UNIXPRIV resource class: 1) The TSS owner defined for the SUPERUSER resource. 2) There are no TSS rules that allow access to the SUPERUSER resource. 3) There is no TSS rule for CHOWN.UNRESTRICTED defined. 4) The TSS rules for each of the SUPERUSER resources listed in the UNIXPRIV CLASS RESOURCES Table in the z/OS STIG Addendum, restrict access to appropriate system tasks or systems programming personnel. Sample Commands: TSS ADD(dept) UNIXPRIV(SUPERUSE) TSS PERMIT() UNIXPRIV(SUPERUSER.FILESYS.) ACCESS(READ) /* where SUPERUSER.FILESYS. represents one of the resources listed in the UNIXPRIV CLASS RESOURCES table in the Addendum */ To determine the current active setting of CHOWNURS, issue a TSS MODIFY STATUS(BASE) command.

Fix Text (F-19110r1_fix)

The IAO will ensure that all SUPERUSER resources for the UNIXPRIV resource class are restricted to appropriate system tasks and/or system programming personnel.

Review the following items for the UNIXPRIV resource class:

1) The TSS owner defined for the SUPERUSER resource.
2) There are no TSS rules that allow access to the
SUPERUSER resource.
3) There is no TSS rule for CHOWN.UNRESTRICTED defined.
4) The TSS rules for each of the SUPERUSER resources listed in the UNIXPRIV CLASS RESOURCES Table in the z/OS STIG Addendum, restrict access to appropriate system tasks or systems programming personnel.

Sample Commands:

TSS ADD(dept) UNIXPRIV(SUPERUSE)
TSS PERMIT() UNIXPRIV(SUPERUSER.FILESYS.) ACCESS(READ)
/* where SUPERUSER.FILESYS. represents one of the resources listed in the UNIXPRIV CLASS RESOURCES table in the Addendum */

To determine the current active setting of CHOWNURS, issue a TSS MODIFY STATUS(BASE) command.