STIGQter STIGQter: STIG Summary: IBM z/OS ACF2 Security Technical Implementation Guide Version: 8 Release: 2 Benchmark Date: 23 Apr 2021:

IBM z/OS must not allow non-existent or inaccessible LINKLIST libraries.

DISA Rule

SV-223562r533198_rule

Vulnerability Number

V-223562

Group Title

SRG-OS-000368-GPOS-00154

Rule Version

ACF2-OS-000260

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Review all entries contained in the LINKLIST for the actual existence of each library. Develop a plan of action to correct deficiencies.

The Linklist is a default set of libraries that MVS searches for a specified program. This facility is used so that a user does not have to know the library names in which utility types of programs are stored. Control over membership in the Linklist is specified within the operating system. The data set SYS1.PARMLIB(LNKLSTxx) is used to specify the library names. (The xx is the suffix designated by the LNK parameter in the IEASYSxx member of SYS1.PARMLIB, or overridden by the computer operator at IPL.)

Use the following recommendations and techniques to control the exposures created by the LINKLIST facility:

-Avoid inclusion of sensitive libraries in the LNKLSTxx member unless absolutely required.

-The LNKLSTxx and PROGxx (LNKLST entries) members will contain only required libraries. On a semiannual basis, Software Support should review the volume serial numbers, and should verify them in accordance with the system catalog. Software Support will remove all non-existent libraries. The ISSO should modify and/or delete the rules associated with these libraries.

Check Contents

From and ISPF Command line enter:
TSO ISRDDN LINKLIST

Review the list.

If there are any DUMMY entries i.e., inaccessible LINKLINK libraries, this is a finding.

Vulnerability Number

V-223562

Documentable

False

Rule Version

ACF2-OS-000260

Severity Override Guidance

From and ISPF Command line enter:
TSO ISRDDN LINKLIST

Review the list.

If there are any DUMMY entries i.e., inaccessible LINKLINK libraries, this is a finding.

Check Content Reference

M

Target Key

4100

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