RHEL 10 must not allow users to override Secure Shell (SSH) environment variables.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-281267RHEL-10-700640SV-281267r1184767_ruleCCI-000381high
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.
STIGDate
Red Hat Enterprise Linux 10 Security Technical Implementation Guide2026-03-11

Related Frameworks

3 paths across 3 frameworks
NIST 800-531 mapping
CM-7
1.00
  • DISA · V1R1 · disa_xccdf · related
  • DISA · 2025-01-23 · disa_cci_list · equivalent
NIST 800-1711 mapping
3.4.6
1.00
  • DISA · V1R1 · disa_xccdf · related
  • DISA · 2025-01-23 · disa_cci_list · equivalent
  • NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent
CCI1 mapping
CCI-000381
1.00
  • DISA · V1R1 · disa_xccdf · related

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