The ESXi host must use DOD-approved certificates.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258784	ESXI-80-000229	SV-258784r959010_rule		Medium

Description
The default self-signed host certificate issued by the VMware Certificate Authority (VMCA) must be replaced with a DOD-approved certificate when the host will be accessed directly, such as during a virtual machine (VM) console connection. The use of a DOD certificate on the host assures clients the service they are connecting to is legitimate and properly secured.

STIG	Date
VMware vSphere 8.0 ESXi Security Technical Implementation Guide	2024-07-11

Details

Check Text ( C-62524r933411_chk )
From the vSphere Client, go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Certificate. If the issuer is not a DOD-approved certificate authority, this is a finding. If the host will never be accessed directly (virtual machine console connections bypass vCenter), this is not a finding.

Fix Text (F-62433r933412_fix)
Join the ESXi host to vCenter before replacing the certificate. Obtain a DOD-issued certificate and private key for the host following the requirements below: Key size: 2048 bits or more (PEM encoded) Key format: PEM VMware supports PKCS8 and PKCS1 (RSA keys) x509 version 3 SubjectAltName must contain DNS Name= CRT (Base-64) format Contains the following Key Usages: Digital Signature, Non Repudiation, Key Encipherment Start time of one day before the current time CN (and SubjectAltName) set to the host name (or IP address) that the ESXi host has in the vCenter Server inventory From the vSphere Web Client, select the ESXi host's vCenter Server >> Configure >> System >> Advanced Settings. Select the "vpxd.certmgmt.mode" value and ensure it is set to "custom". Put the host into maintenance mode. Temporarily enable Secure Shell (SSH) on the host. Use Secure Copy Protocol (SCP) to transfer the new certificate and key to /tmp. SSH to the host. Back up the existing certificate and key: # mv /etc/vmware/ssl/rui.crt /etc/vmware/ssl/rui.crt.bak # mv /etc/vmware/ssl/rui.key /etc/vmware/ssl/rui.key.bak Copy the new certificate and key to "/etc/vmware/ssl/" and rename them to "rui.crt" and "rui.key" respectively. Restart management agents to implement the new certificate: # services.sh restart

Fix Text (F-62433r933412_fix)

Join the ESXi host to vCenter before replacing the certificate.

Obtain a DOD-issued certificate and private key for the host following the requirements below:

Key size: 2048 bits or more (PEM encoded)

Key format: PEM
VMware supports PKCS8 and PKCS1 (RSA keys)
x509 version 3

SubjectAltName must contain DNS Name=

CRT (Base-64) format

Contains the following Key Usages: Digital Signature, Non Repudiation, Key Encipherment

Start time of one day before the current time

CN (and SubjectAltName) set to the host name (or IP address) that the ESXi host has in the vCenter Server inventory

From the vSphere Web Client, select the ESXi host's vCenter Server >> Configure >> System >> Advanced Settings.

Select the "vpxd.certmgmt.mode" value and ensure it is set to "custom".

Put the host into maintenance mode.

Temporarily enable Secure Shell (SSH) on the host. Use Secure Copy Protocol (SCP) to transfer the new certificate and key to /tmp. SSH to the host. Back up the existing certificate and key:

# mv /etc/vmware/ssl/rui.crt /etc/vmware/ssl/rui.crt.bak
# mv /etc/vmware/ssl/rui.key /etc/vmware/ssl/rui.key.bak

Copy the new certificate and key to "/etc/vmware/ssl/" and rename them to "rui.crt" and "rui.key" respectively.

Restart management agents to implement the new certificate:

# services.sh restart