STIGQter: STIG Summary: Citrix XenDesktop 7.x Delivery Controller Security Technical Implementation Guide Version: 1 Release: 3 Benchmark Date: 24 Apr 2020:

Delivery Controller must implement NIST FIPS-validated cryptography for the following: to provision digital signatures; to generate cryptographic hashes; and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.

DISA Rule

SV-96123r2_rule

Vulnerability Number

V-81409

Group Title

SRG-APP-000514

Rule Version

CXEN-DC-001225

Severity

CAT I

CCI(s)

CCI-002450 - The information system implements organization-defined cryptographic uses and type of cryptography required for each use in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.

Weight

Fix Recommendation

Obtain and install root certificate(s) for server certificates installed on Desktop/Server VDAs, SQL Server(s), Storefront, and VM Host (VMware VCenter, Hyper-V, XenServer).

To install a TLS server certificate on the Delivery Controller and to configure a port with TLS 1.x:
1. Log on to the Delivery Controller server with a domain account that has Administrator rights.
2. Obtain a TLS server certificate and install it on the Delivery Controller using Microsoft server instructions.
3. Configure the Delivery Controller with the certificate.

When the Server Certificate is installed on IIS, set the Bindings to enable HTTPS on IIS by completing the following procedure:
1. Select the IIS site that you want to enable HTTPS and select "Bindings" under "Edit Site".
2. Click "Add", select "Type" as https and port number as "443". Select the SSL Certificate that was installed and click "OK".
3. Open the Registry Editor on the XenDesktop Controller and find the following key name:
HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\DesktopServer
4. Verify that XmlServicesSslPort registry key exists with the correct value for SSL port. By default, it is set to "443".
5. Change the XML service port using PowerShell or by running the following command:
BrokerService –WiSslPort <port number>

Notes:
a) If you decide to change the XML service port number on the XenDesktop controller, update the IIS port number as well under "Bindings" to match the new value.
b) On XenDesktop 7.11, the parameter of brokerservice.exe has changed from "wisslport" to "storefronttlsport". The brokerservice.exe is found in c:\program files\citrix\broker\service.
A reboot of the Delivery Controller is needed for this to take effect.

To change the default VDA registration port:
1. Log on to the Delivery Controller server with a domain account that has Administrator rights.
2. Open the command prompt window and type these commands:
%SystemDrive%
Cd %ProgramFiles%\Citrix\Broker\Service
BrokerService.exe –VDAport 8888
3. Launch Server Manager from the Start menu.
4. In the Server Manager, go to the "Local Server" properties window and edit the "Windows Firewall" setting. Click "Advanced Settings".
5. Click "Inbound Rules".
6. Create a new inbound rule with the following settings:
a) In the Rule type screen, click "Port". Click "Next".
b) In the Protocol and Ports screen, select "Specific local ports" and type "8888". Click "Next".
c) In the Action screen, accept the default value "Allow the connection" and click "Next".
d) In the Profile screen, accept the default values and click "Next".
e) In the Name screen, type a name for the rule (example: Citrix VDA Registration Port)
and click "Finish".

For correct Cipher Suite order per DoD guidance:
Apply the following to Computers OU containing XenDesktop infrastructure:
- XD2017 CC - Computer - SSL Ciphersuite Order

To configure the SSL Cipher Suite Order Group Policy setting manually, follow these steps:
1. At a command prompt, enter "gpedit.msc", and press "Enter". The Local Group Policy Editor is displayed.
2. Go to Computer Configuration >> Administrative Templates >> Network >> SSL Configuration Settings.
3. Under SSL Configuration Settings, select "SSL Cipher Suite Order".
4. In the SSL Cipher Suite Order pane, scroll to the bottom. Follow the instructions that are labeled "How to modify this setting".

Check Contents

Enforcement is via FIPS encryption. To verify, open the Registry Editor on the XenDesktop Delivery Controller and find the following key name: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\DesktopServer

1. Verify that the XmlServicesSslPort registry key exists with the correct value for SSL port. By default, it is set to "443".
2. Verify XmlServicesEnableNonSsl is set to "0".
3. Verify the corresponding registry value to ignore HTTPS traffic, XmlServicesEnableSsl, is not set to "0".

If "XmlServicesSslPort" is not set to the desired port, this is a finding.

If "XmlServicesEnableNonSsl" is not set to "0", this is a finding.

If XmlServicesEnableSsl is not set to "1", this is a finding.

To verify the FIPS Cipher Suites used:
1. From the Group Policy Management Console, go to Computer Configuration >> Administrative Templates >> Networks >> SSL Configuration Settings.
2. Double-click "SSL Cipher Suite Order" and verify the "Enabled" option is checked.
3. Verify the correct Cipher Suites are listed in the correct order per current DoD guidelines.

If the "Enabled" option is not checked or the correct Cipher Suites are not listed in the correct order per current DoD guidelines, this is a finding.

DISA Rule

Vulnerability Number

Group Title

Rule Version

Severity

CCI(s)

Weight

Fix Recommendation

Check Contents

Vulnerability Number

Documentable

Rule Version

Severity Override Guidance

Check Content Reference

Target Key

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