The Photon operating system must configure Secure Shell (SSH) to disallow compression of the encrypted session stream.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-258878 | SRG-OS-000480-GPOS-00227 | PHTN-40-000215 | SV-258878r991589_rule | 2024-07-11 | 2 |
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.
ℹ️ Check
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
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