Vulnerability Discussion

Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered.

This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification.

Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190

Check

Verify SSH is loaded and active with the following command:

$ sudo systemctl status sshd

sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled)
Active: active (running) since Tue 2015-11-17 15:17:22 EST; 4 weeks 0 days ago
Main PID: 1348 (sshd)
CGroup: /system.slice/sshd.service
1053 /usr/sbin/sshd -D

If "sshd" does not show a status of "active" and "running", this is a finding.

If the "SSH server" package is not installed, this is a finding.

Fix

Install SSH packages onto the host with the following commands:

$ sudo yum install openssh-server.x86_64

Configure the SSH service to automatically start after reboot with the following command:

$ sudo systemctl enable sshd.service