The ESXi host must enable bidirectional Challenge-Handshake Authentication Protocol (CHAP) authentication for Internet Small Computer Systems Interface (iSCSI) traffic.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-258747 | ESXI-80-000145 | SV-258747r933302_rule | CCI-001967 | medium |
| Description | ||||
| When enabled, vSphere performs bidirectional authentication of both the iSCSI target and host. When not authenticating both the iSCSI target and host, there is potential for a man-in-the-middle attack, in which an attacker might impersonate either side of the connection to steal data. Bidirectional authentication mitigates this risk. | ||||
| STIG | Date | |||
| VMware vSphere 8.0 ESXi Security Technical Implementation Guide | 2023-10-11 | |||
Details
Check Text (C-258747r933302_chk)
If iSCSI is not used, this is not applicable.
From the vSphere Client, go to Hosts and Clusters.
Select the ESXi Host >> Configure >> Storage >> Storage Adapters.
Select the iSCSI adapter >> Properties >> Authentication >> Method.
View the CHAP configuration and verify CHAP is required for target and host authentication.
or
From a PowerCLI command prompt while connected to the ESXi host, run the following command:
Get-VMHost | Get-VMHostHba | Where {$_.Type -eq "iscsi"} | Select AuthenticationProperties -ExpandProperty AuthenticationProperties
If iSCSI is used and CHAP is not set to "required" for both the target and host, this is a finding.
If iSCSI is used and unique CHAP secrets are not used for each host, this is a finding.
Fix Text (F-62396r933301_fix)
From the vSphere Client, go to Hosts and Clusters.
Select the ESXi Host >> Configure >> Storage >> Storage Adapters.
Select the iSCSI adapter >> Properties >> Authentication.
Click "Edit...". Set "Authentication Method" to "Use bidirectional CHAP" and enter a unique secret for each traffic flow direction.
or
From a PowerCLI command prompt while connected to the ESXi host, run the following command:
Get-VMHost | Get-VMHostHba | Where {$_.Type -eq "iscsi"} | Set-VMHostHba -ChapType Required -ChapName "chapname" -ChapPassword "password" -MutualChapEnabled $true -MutualChapName "mutualchapname" -MutualChapPassword "mutualpassword"