The ESXi host Secure Shell (SSH) daemon must not allow host-based authentication.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258761	SRG-OS-000480-VMM-002000	ESXI-80-000202	SV-258761r933344_rule	2023-10-11	1

Description
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. SSH's cryptographic host-based authentication is more secure than ".rhosts" authentication since hosts are cryptographically authenticated. However, it is not recommended that hosts unilaterally trust one another, even within an organization.

ℹ️ Check
From an ESXi shell, run the following command: # esxcli system ssh server config list -k hostbasedauthentication or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $esxcli.system.ssh.server.config.list.invoke() \| Where-Object {$_.Key -eq 'hostbasedauthentication'} Example result: hostbasedauthentication no If "hostbasedauthentication" is not configured to "no", this is a finding.

ℹ️ Check

From an ESXi shell, run the following command: # esxcli system ssh server config list -k hostbasedauthentication or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $esxcli.system.ssh.server.config.list.invoke() | Where-Object {$_.Key -eq 'hostbasedauthentication'} Example result: hostbasedauthentication no If "hostbasedauthentication" is not configured to "no", this is a finding.

✔️ Fix
From an ESXi shell, run the following command: # esxcli system ssh server config set -k hostbasedauthentication -v no or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $arguments = $esxcli.system.ssh.server.config.set.CreateArgs() $arguments.keyword = 'hostbasedauthentication' $arguments.value = 'no' $esxcli.system.ssh.server.config.set.Invoke($arguments)

✔️ Fix

From an ESXi shell, run the following command: # esxcli system ssh server config set -k hostbasedauthentication -v no or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $arguments = $esxcli.system.ssh.server.config.set.CreateArgs() $arguments.keyword = 'hostbasedauthentication' $arguments.value = 'no' $esxcli.system.ssh.server.config.set.Invoke($arguments)