The Photon operating system must configure Secure Shell (SSH) to disallow compression of the encrypted session stream.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-258878 | PHTN-40-000215 | SV-258878r933695_rule | CCI-000366 | medium |
| Description | ||||
| If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection. | ||||
| STIG | Date | |||
| VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide | 2023-10-29 | |||
Details
Check Text (C-258878r933695_chk)
At the command line, run the following command to verify the running configuration of sshd:
# sshd -T|&grep -i Compression
Example result:
compression no
If there is no output or if "Compression" is not set to "delayed" or "no", this is a finding.
Fix Text (F-62527r933694_fix)
Navigate to and open:
/etc/ssh/sshd_config
Ensure the "Compression" line is uncommented and set to the following:
Compression no
At the command line, run the following command:
# systemctl restart sshd.service