IBM z/OS UNIX HFS MapName file security parameters must be properly specified.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-224074	TSS0-US-000010	SV-224074r877912_rule		Medium

Description
Removal of unneeded or non-secure functions, ports, protocols, and services mitigate the risk of unauthorized connection of devices, unauthorized transfer of information, or other exploitation of these resources.

STIG	Date
IBM z/OS TSS Security Technical Implementation Guide	2024-02-22

Details

Check Text ( C-25747r516621_chk )
Refer to the logical parmlib data sets, example: SYS1.PARMLIB(BPXPRMxx), for the following FILESYSTYPE entry: FILESYSTYPE TYPE(AUTOMNT) ENTRYPOINT(BPXTAMD) If the above entry is not found or is commented out in the BPXPRMxx member(s), this is not applicable. From the ISPF Command Shell enter: OMVS cd /etc cat auto.master perform a contents list for the file identified Example: cat u.map Note: The /etc/auto.master HFS file (and the use of Automount) is optional. If the file does not exist, this is not applicable. Note: The setuid parameter and the security parameter have a significant security impact. For this reason these parameters must be explicitly specified and not allowed to default. If each MapName file specifies the "setuid No" and "security Yes" statements for each automounted directory, this is not a finding. If there is any deviation from the required values, this is a finding.

Check Text ( C-25747r516621_chk )

Refer to the logical parmlib data sets, example: SYS1.PARMLIB(BPXPRMxx), for the following FILESYSTYPE entry:

FILESYSTYPE TYPE(AUTOMNT) ENTRYPOINT(BPXTAMD)

If the above entry is not found or is commented out in the BPXPRMxx member(s), this is not applicable.

From the ISPF Command Shell enter:
OMVS
cd /etc
cat auto.master
perform a contents list for the file identified
Example:
cat u.map
Note: The /etc/auto.master HFS file (and the use of Automount) is optional. If the file does not exist, this is not applicable.

Note: The setuid parameter and the security parameter have a significant security impact. For this reason these parameters must be explicitly specified and not allowed to default.

If each MapName file specifies the "setuid No" and "security Yes" statements for each automounted directory, this is not a finding.

If there is any deviation from the required values, this is a finding.

Fix Text (F-25735r516622_fix)
Review the settings in /etc/auto.master and /etc/mapname for z/OS UNIX security parameters and configure the values to conform to the specifications below. The /etc/auto.master HFS file (and the use of Automount) is optional. The setuid parameter and the security parameter have a significant security impact. For this reason these parameters must be explicitly specified and not be allowed to default. Each MapName file will specify the "setuid NO" and "security YES" statements for each automounted directory. If there is a deviation from the required values, documentation must exist for the deviation. "Security NO" disables security checking for file access. "Security NO" is only allowed on test and development domains. "Setuid YES" allows a user to run under a different UID/GID identity. Justification documentation is required to validate the use of "setuid YES".

Fix Text (F-25735r516622_fix)

Review the settings in /etc/auto.master and /etc/mapname for z/OS UNIX security parameters and configure the values to conform to the specifications below.

The /etc/auto.master HFS file (and the use of Automount) is optional.

The setuid parameter and the security parameter have a significant security impact. For this reason these parameters must be explicitly specified and not be allowed to default.

Each MapName file will specify the "setuid NO" and "security YES" statements for each automounted directory.

If there is a deviation from the required values, documentation must exist for the deviation.

"Security NO" disables security checking for file access. "Security NO" is only allowed on test and development domains.

"Setuid YES" allows a user to run under a different UID/GID identity. Justification documentation is required to validate the use of "setuid YES".