IBM RACF must limit Write or greater access to SYS1.NUCLEUS to system programmers only.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223649	RACF-ES-000010	SV-223649r853567_rule		High

Description
This data set contains a large portion of the system initialization (IPL) programs and pointers to the master and alternate master catalog. Unauthorized access could result in the compromise of the operating system environment, ACP, and customer data. Satisfies: SRG-OS-000080-GPOS-00048, SRG-OS-000259-GPOS-00100, SRG-OS-000324-GPOS-00125

STIG	Date
IBM z/OS RACF Security Technical Implementation Guide	2023-12-27

Details

Check Text ( C-25322r514636_chk )
Execute a dataset access list for SYS1.NUCLEUS. If all of the Following are untrue, this is not a finding. If any of the following is true, this is a finding. -The ACP data set rules for SYS1.NUCLEUS do not restrict WRITE or greater access to only z/OS systems programming personnel. -The ACP data set rules for SYS1.NUCLEUS do not specify that all (i.e., failures and successes) WRITE or greater access will be logged.

Check Text ( C-25322r514636_chk )

Execute a dataset access list for SYS1.NUCLEUS.

If all of the Following are untrue, this is not a finding.

If any of the following is true, this is a finding.

-The ACP data set rules for SYS1.NUCLEUS do not restrict WRITE or greater access to only z/OS systems programming personnel.
-The ACP data set rules for SYS1.NUCLEUS do not specify that all (i.e., failures and successes) WRITE or greater access will be logged.

Fix Text (F-25310r514637_fix)
Review access authorization to critical system files. Evaluate the impact of correcting the deficiency. Develop a plan of action and implement the changes required to protect SYS1.NUCLEUS. Configure the WRITE or greater access to SYS1.NUCLEUS to be limited to system programmers only and all WRITE or greater access is logged.