Check: ZUSS0023
zOS TSS STIG:
ZUSS0023
(in versions v6 r43 through v6 r30)
Title
z/OS UNIX SUPERUSER resource must be protected in accordance with guidelines. (Cat I impact)
Discussion
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.
Check Content
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
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(<SYSPAUDT>) 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.
Additional Identifiers
Rule ID: SV-19749r3_rule
Vulnerability ID: V-6972
Group Title: ZUSS0023
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000213 |
Enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. |
CCI-001764 |
Prevent program execution in accordance with organization-defined policies, rules of behavior, and/or access agreements regarding software program usage and restrictions; rules authorizing the terms and conditions of software program usage. |