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Dynamic lists must be protected in accordance with proper security requirements.


Overview

Finding ID Version Rule ID IA Controls Severity
V-36 ACP00270 SV-36r8_rule High
Description
Dynamic lists provide a method of making z/OS system changes without interrupting the availability of the operating system. Failure to properly control access to these facilities could result in unauthorized personnel modifying sensitive z/OS lists. This exposure may threaten the integrity and availability of the operating system environment, and compromise the confidentiality of customer data.
STIG Date
z/OS ACF2 STIG 2019-12-12

Details

Check Text ( C-5438r5_chk )
Refer to the following report produced by the ACF2 Data Collection and Data Set and Resource Data Collection:

- SENSITVE.RPT(FACILITY)
- ACF2CMDS.RPT(RESOURCE) – Alternate report

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

- PDI(ACP00270)

Verify that the accesses for CSV-prefixed resources are properly restricted. If the following guidance is true, this is not a finding.

___ The ACF2 resources and/or generic equivalent are defined with a default access of PREVENT.

___ The ACF2 resources and/or generic equivalent identified below will be defined with LOG and SERVICE(UPDATE) access restricted to system programming personnel:

CSVAPF.
CSVAPF.MVS.SETPROG.FORMAT.DYNAMIC
CSVAPF.MVS.SETPROG.FORMAT.STATIC
CSVDYLPA.
CSVDYNEX.
CSVDYNEX.LIST
CSVDYNL.
CSVDYNL.UPDATE.LNKLST
CSVLLA.

___ The ACF2 CSVDYNEX.LIST resource and/or generic equivalent will be defined with LOG and SERVICE(UPDATE) access restricted to system programming personnel.

___ The ACF2 CSVDYNEX.LIST resource and/or generic equivalent will be defined with SERVICE(READ) access restricted to auditors.

___ If the products CICS and/or CONTROL-O are on the system, the ACF2 access to the CSVLLA resource and/or generic equivalent will be defined with LOG and SERVICE(UPDATE) access restricted to the CICS and CONTROL-O STC logonids.

___ If any software product requires access to dynamic LPA updates on the system, the ACF2 access to the CSVDYLPA resource and/or generic equivalent will be defined with AUDIT(ALL) and UPDATE only after the product has been validated with the appropriate STIG or SRG for compliance AND receives documented and filed authorization that details the need and any accepted risks from the site ISSM or equivalent security authority.

Note: In the above, SERVICE(UPDATE) can be substituted with ADD, CONTROL, or LOG/ALLOW. Review the rules definitions in the ACF2 documentation when specifying SERVICE(UPDATE).
Fix Text (F-35197r5_fix)
Ensure that the Dynamic List resources are defined to the IBMFAC resource class and protected. Only system programmers and a limited number of authorized users and Approved authorized Started Tasks are able to issue these commands. All access is logged.

(Note: The resource class, resources, and/or resource prefixes identified below are examples of a possible installation. The resource class, actual resources, and/or prefixes are determined when the product is actually installed on a system through the product’s installation guide and can be site specific.)

The required CSV-prefixed Facility Class resources are listed below. These resources and/or generic equivalents should be defined and permitted as required with only z/OS systems programmers and logging enabled. Minimum required list of CSV-prefixed resources:

CSVAPF.-
CSVAPF.MVS.SETPROG.FORMAT.DYNAMIC
CSVAPF.MVS.SETPROG.FORMAT.STATIC
CSVDYLPA.-
CSVDYLPA.ADD.-
CSVDYLPA.DELETE.-
CSVDYNEX.-
CSVDYNEX.LIST
CSVDYNL.-
CSVDYNL.UPDATE.LNKLST
CSVLLA.-

Limit authority to those resources to z/OS systems programmers. Restrict to the absolute minimum number of personnel with LOG and SERVICE(UPDATE) access.

Sample commands are shown here to accomplish one set of resources:

$KEY(CSVAPF) TYPE(FAC)
MVS.SETPROG.- UID(syspaudt) LOG
MVS.SETPROG.FORMAT.DYNAMIC.- UID(syspaudt) LOG
MVS.SETPROG.FORMAT.STATIC.- UID(syspaudt) LOG
MVS.SETPROG.FORMAT.- UID(syspaudt) LOG
MVS.SETPROG.FORMAT.- UID(*) PREVENT
- UID(syspaudt) LOG
- UID(*) PREVENT

SET R(FAC)
COMPILE 'ACF2.xxxx.FAC(CSVAPF)' STORE

F ACF2,REBUILD(FAC)

The CSVDYLPA.ADD resource can be permitted to BMC Mainview, CA 1, and CA Common Services STC logonids with LOG and SERVICE(UPDATE) access.

The CSVDYLPA.DELETE resource can be permitted to CA 1 and CA Common Services STC logonids with LOG and SERVICE(UPDATE) access.

Sample commands are shown here to accomplish one set of resources:

$KEY(CSVDYLPA) TYPE(FAC)
ADD.- UID(syspaudt) LOG SERVICE(UPDATE)
ADD.- UID(BMC Mainview STC) LOG SERVICE(UPDATE)
ADD.- UID(CA 1 STC) LOG SERVICE(UPDATE)
ADD.- UID(CCS STC) LOG SERVICE(UPDATE)
DELETE.- UID(syspaudt) LOG SERVICE(UPDATE)
DELETE.- UID(CA 1 STC) LOG SERVICE(UPDATE)
DELETE.- UID(CCS STC) LOG SERVICE(UPDATE)
- UID(syspaudt) LOG
- UID(*) PREVENT

SET R(FAC)
COMPILE 'ACF2.xxxx.FAC(CSVDYLPA)' STORE

F ACF2,REBUILD(FAC)

The CSVDYNEX.LIST resource and/or generic equivalent will be defined with LOG and SERVICE(UPDATE) access restricted to system programming personnel.

The CSVDYNEX.LIST resource and/or generic equivalent will be defined with SERVICE(READ) access with ALLOW restricted to auditors.

Sample commands are shown here to accomplish this:

$KEY(CSVDYNEX) TYPE(FAC)
LIST.- UID(syspaudt) LOG
LIST.- UID(audtaudt) SERVICE(READ) ALLOW
- UID(syspaudt) LOG
- UID(*) PREVENT

SET R(FAC)
COMPILE 'ACF2.xxxx.FAC(CSVDYNEX)' STORE

F ACF2,REBUILD(FAC)

The CSVLLA resource can be permitted to CICS and CONTROL-O STC logonids with LOG and SERVICE(UPDATE) access.

Sample commands are shown here to accomplish one set of resources:

$KEY(CSVLLA) TYPE(FAC)
- UID(syspaudt) LOG
- UID(CICS STC logonids) LOG SERVICE(UPDATE)
- UID(CONTROL-O STC logonid) LOG SERVICE(UPDATE)
- UID(*) PREVENT

SET R(FAC)
COMPILE 'ACF2.xxxx.FAC(CSVLLA)' STORE

F ACF2,REBUILD(FAC)