STIGUI
V-223649CAT I — High severitySV-223649r1268226_rule

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

Rule version RACF-ES-000010 · STIG v9 · 2026-09-01

Discussion

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

Check

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

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.

Identifiers

Group ID
V-223649
Group title
SRG-OS-000080-GPOS-00048
Rule ID
SV-223649r1268226_rule
Check ID
C-25322r514636_chk
Fix ID
F-25310r514637_fix