The ESXi host must verify certificates for SSL syslog endpoints.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258779	SRG-OS-000480-VMM-002000	ESXI-80-000224	SV-258779r933398_rule	2023-10-11	1

Description
When sending syslog data to a remote host, ESXi can be configured to use any combination of TCP, UDP, and SSL transports. When using SSL, the server certificate must be validated to ensure that the host is connecting to a valid syslog server.

ℹ️ Check
If SSL is not used for a syslog target, this is not applicable. From the vSphere Client, go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Select the "Syslog.global.logCheckSSLCerts" value and verify it is set to "true". or From a PowerCLI command prompt while connected to the ESXi host, run the following command: Get-VMHost \| Get-AdvancedSetting -Name Syslog.global.logCheckSSLCerts If the "Syslog.global.logCheckSSLCerts" setting is not set to "true", this is a finding.

ℹ️ Check

If SSL is not used for a syslog target, this is not applicable. From the vSphere Client, go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Select the "Syslog.global.logCheckSSLCerts" value and verify it is set to "true". or From a PowerCLI command prompt while connected to the ESXi host, run the following command: Get-VMHost | Get-AdvancedSetting -Name Syslog.global.logCheckSSLCerts If the "Syslog.global.logCheckSSLCerts" setting is not set to "true", this is a finding.

✔️ Fix
To configure SSL syslog endpoint certificate checking, it must be turned on and the trusted certificate chain must be added to ESXi's trusted store. From the vSphere Client go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Click "Edit". Select the "Syslog.global.logCheckSSLCerts" value and configure it to "true". Copy the PEM formatted trusted CA certificate so that is accessible to the host and append the contents to /etc/vmware/ssl/castore.pem by running the following command: # <path/to/cacert> >> /etc/vmware/ssl/castore.pem or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: Get-VMHost \| Get-AdvancedSetting -Name Syslog.global.logCheckSSLCerts \| Set-AdvancedSetting -Value "true" Copy the PEM formatted trusted CA certificate so that is accessible to the host. $esxcli = Get-EsxCli -v2 $arguments = $esxcli.system.security.certificatestore.add.CreateArgs() $arguments.filename = <path/to/cacert> $esxcli.system.security.certificatestore.add.Invoke($arguments)

✔️ Fix

To configure SSL syslog endpoint certificate checking, it must be turned on and the trusted certificate chain must be added to ESXi's trusted store. From the vSphere Client go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Click "Edit". Select the "Syslog.global.logCheckSSLCerts" value and configure it to "true". Copy the PEM formatted trusted CA certificate so that is accessible to the host and append the contents to /etc/vmware/ssl/castore.pem by running the following command: # <path/to/cacert> >> /etc/vmware/ssl/castore.pem or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: Get-VMHost | Get-AdvancedSetting -Name Syslog.global.logCheckSSLCerts | Set-AdvancedSetting -Value "true" Copy the PEM formatted trusted CA certificate so that is accessible to the host. $esxcli = Get-EsxCli -v2 $arguments = $esxcli.system.security.certificatestore.add.CreateArgs() $arguments.filename = <path/to/cacert> $esxcli.system.security.certificatestore.add.Invoke($arguments)