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

IBM z/OS Attributes of UNIX user accounts used for account modeling must be defined in accordance with security requirements.

DISA Rule

SV-223638r533198_rule

Vulnerability Number

V-223638

Group Title

SRG-OS-000104-GPOS-00051

Rule Version

ACF2-US-000230

Severity

CAT II

CCI(s)

• CCI-000764 - The information system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users).

Weight

10

Fix Recommendation

Define DFTUSER or MODLUSER or BPX.UNIQUE.USER user account to be defined as follows:

A non-writable HOME directory:
Shell program specified as "/bin/echo" or "/bin/false"

Note: The shell program must have one of the specified values. The HOME directory must have a value (i.e., not be allowed to default).

Example:
SET PROFILE(USER) DIV(OMVS)
LIST OMVS

INSERT OMVS HOME(/) OMVSPGM(/bin/false) UID(0)

Check Contents

If this is a Classified system, this is Not Applicable.

From an ACF2 command line enter:
SET CONTROL(GSO)
SHOW UNIXOPTS

Alternately:
Refer to the following report produced by the ACF2 Data Collection:
- ACF2CMDS.RPT(ACFGSO)
- ACF2CMDS.RPT(OMVSUSER)

Note: This check applies to any user identifier (LOGONID) used to model OMVS access on the mainframe. This includes any DFTUSER; MODLUSER and BPX.UNIQUE.USER. If MODLUSER is specified then UNIQUSER must be specified.

If DFTUSER or MODLUSER is not defined in the UNIXOPTS record, this is not a finding.

If ALL user identifiers (LOGONID) defined to DFTUSER or MODLUSER. or BPX.UNIQUE.USER user account is defined as follows, this is not a finding:

A non-writable HOME directory:
Shell program specified as “/bin/echo” or “/bin/false”

Note: The shell program must have one of the specified values. The HOME directory must have a value (i.e., not be allowed to default).

Vulnerability Number

V-223638

Documentable

False

Rule Version

ACF2-US-000230

Severity Override Guidance

If this is a Classified system, this is Not Applicable.

From an ACF2 command line enter:
SET CONTROL(GSO)
SHOW UNIXOPTS

Alternately:
Refer to the following report produced by the ACF2 Data Collection:
- ACF2CMDS.RPT(ACFGSO)
- ACF2CMDS.RPT(OMVSUSER)

Note: This check applies to any user identifier (LOGONID) used to model OMVS access on the mainframe. This includes any DFTUSER; MODLUSER and BPX.UNIQUE.USER. If MODLUSER is specified then UNIQUSER must be specified.

If DFTUSER or MODLUSER is not defined in the UNIXOPTS record, this is not a finding.

If ALL user identifiers (LOGONID) defined to DFTUSER or MODLUSER. or BPX.UNIQUE.USER user account is defined as follows, this is not a finding:

A non-writable HOME directory:
Shell program specified as “/bin/echo” or “/bin/false”

Note: The shell program must have one of the specified values. The HOME directory must have a value (i.e., not be allowed to default).

Check Content Reference

M

Target Key

4100

Comments