UCF STIG Viewer Logo

The Photon operating system must configure Secure Shell (SSH) to disallow compression of the encrypted session stream.


Finding ID Version Rule ID IA Controls Severity
V-258878 PHTN-40-000215 SV-258878r933695_rule Medium
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.
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide 2023-10-29


Check Text ( C-62618r933693_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:


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