cyberstrikeus CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.2.20
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The PermitUserEnvironment option allows users to present environment options to the SSH daemon.
Rationale
Permitting users the ability to set environment variables through the SSH daemon could potentially allow users to bypass security controls (e.g. setting an execution path that has SSH executing trojan'd programs).
Audit Procedure
Command Line
Run the following command and verify the output:
sshd -T | grep -i permituserenvironment
Expected Result
permituserenvironment no
Remediation
Command Line
Edit the /etc/ssh/sshd_config file to set the parameter as follows:
PermitUserEnvironment no
Default Value
PermitUserEnvironment no
References
- NIST SP 800-53 Rev. 5: CM-7
CIS Controls
v8 - 4.8 Uninstall or Disable Unnecessary Services on Enterprise Assets and Software.
v7 - 9.2 Ensure Only Approved Ports, Protocols, and Services Are Running.
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Assessment Status
Automated