RHEL 10 must not allow users to override Secure Shell (SSH) environment variables.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-281267 | RHEL-10-700640 | SV-281267r1184767_rule | CCI-000381 | high |
| Description | ||||
| SSH environment options potentially allow users to bypass access restriction in some configurations. OpenSSH uses the first occurrence of a keyword it sees, and drop-in files are read in lexicographical order at the start of the configuration. Red Hat recommends using drop-in files rather than changing base configuration files. | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 10 Security Technical Implementation Guide | 2026-03-11 | |||
Details
Check Text (C-281267r1184767_chk)
Verify RHEL 10 disables unattended or automatic login via SSH with the following command:
$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permituserenvironment'
/etc/ssh/sshd_config.d/10-stig.conf:PermitUserEnvironment no
Verify the runtime setting with the following command:
$ sudo sshd -T | grep -i permituserenvironment
permituserenvironment no
If the "PermitUserEnvironment" keyword is not set to "no" in a drop-in that lexicographically precedes 50-redhat.conf, or if no output is returned, this is a finding.
Fix Text (F-85733r1166752_fix)
Configure RHEL 10 to disable unattended or automatic login via SSH.
In "/etc/ssh/sshd_config.d", create a drop file that will lexicographically precede 50-redhat.conf and add the following line:
PermitUserEnvironment no
Restart the SSH daemon with the following command for the setting to take effect:
$ sudo systemctl restart sshd.service