RHEL 9 system accounts must not have an interactive login shell.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258046	SRG-OS-000480-GPOS-00227	RHEL-09-411035	SV-258046r991589_rule	2025-02-27	2

Description
Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.

ℹ️ Check
Verify that system accounts must not have an interactive login shell with the following command: $ awk -F: '($3<1000){print $1 ":" $3 ":" $7}' /etc/passwd root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin Identify the system accounts from this listing that do not have a nologin shell. If any system account (other than the root account) has a login shell and it is not documented with the information system security officer (ISSO), this is a finding.

ℹ️ Check

Verify that system accounts must not have an interactive login shell with the following command: $ awk -F: '($3<1000){print $1 ":" $3 ":" $7}' /etc/passwd root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin Identify the system accounts from this listing that do not have a nologin shell. If any system account (other than the root account) has a login shell and it is not documented with the information system security officer (ISSO), this is a finding.

✔️ Fix
Configure RHEL 9 so that all noninteractive accounts on the system do not have an interactive shell assigned to them. If the system account needs a shell assigned for mission operations, document the need with the information system security officer (ISSO). Run the following command to disable the interactive shell for a specific noninteractive user account: Replace <user> with the user that has a login shell. $ sudo usermod --shell /sbin/nologin <user> Do not perform the steps in this section on the root account. Doing so will cause the system to become inaccessible.

✔️ Fix

Configure RHEL 9 so that all noninteractive accounts on the system do not have an interactive shell assigned to them. If the system account needs a shell assigned for mission operations, document the need with the information system security officer (ISSO). Run the following command to disable the interactive shell for a specific noninteractive user account: Replace <user> with the user that has a login shell. $ sudo usermod --shell /sbin/nologin <user> Do not perform the steps in this section on the root account. Doing so will cause the system to become inaccessible.