Description of Problem

Multiple vulnerabilities have been discovered in Citrix ADC (formerly known as NetScaler ADC) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO. These vulnerabilities, if exploited, could result in the following security issues:

CVE-ID	Description	CWE	Affected Products	Pre-conditions
CVE-2021-22919	Limited disk space consumption on the appliance	CWE-400: Uncontrolled Resource Consumption	Citrix ADC, Citrix Gateway, Citrix SD-WAN WANOP Edition	Unauthenticated attacker must be able to reach the management GUI
CVE-2021-22920	SAML authentication hijack through a phishing attack to steal a valid user session	CWE-284: Improper access control	Citrix ADC, Citrix Gateway	Citrix ADC or Citrix Gateway must be configured as a SAML SP
CVE-2021-22927	Session fixation by an authorized user on SAML SP	CWE-384: Session Fixation	Citrix ADC, Citrix Gateway	Citrix ADC or Citrix Gateway must be configured as a SAML SP

The following supported versions of Citrix ADC, Citrix Gateway, and Citrix SD-WAN WANOP Edition are affected by CVE-2021-22919:

Citrix ADC and Citrix Gateway 13.0 before 13.0-82.45
Citrix ADC and Citrix Gateway 12.1 before 12.1-62.27
Citrix ADC and NetScaler Gateway 11.1 before 11.1-65.22
Citrix ADC 12.1-FIPS before 12.1-55.247
Citrix SD-WAN WANOP Edition 11.4 before 11.4.0.a
Citrix SD-WAN WANOP Edition 11.3 before 11.3.2.a
Citrix SD-WAN WANOP Edition 11.2 before 11.2.3.b
Citrix SD-WAN WANOP Edition 10.2 before 10.2.9.b

The following supported versions of Citrix ADC and Citrix Gateway are affected by CVE-2021-22920:

Citrix ADC and Citrix Gateway 13.0-82.42
Citrix ADC and Citrix Gateway 12.1-62.25

The following supported versions of Citrix ADC and Citrix Gateway are affected by CVE-2021-22927:

Citrix ADC and Citrix Gateway 13.0 before 13.0-82.45
Citrix ADC and Citrix Gateway 12.1 before 12.1-62.27
Citrix ADC and NetScaler Gateway 11.1 before 11.1-65.22
Citrix ADC 12.1-FIPS before 12.1-55.247

These issues have already been addressed in Citrix managed Cloud services such as Citrix Gateway Service and Citrix Secure Workspace Access. Customers using Citrix managed Cloud services do not need to take any action.

What Customers Should Do

The following supported versions of Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP Edition address CVE-2021-22919:

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1
Citrix ADC and NetScaler Gateway 11.1-65.22 and later releases of 11.1
Citrix ADC 12.1-FIPS 12.1-55.247 and later releases of 12.1-FIPS
Citrix SD-WAN WANOP Edition 11.4.0a and later releases of 11.4
Citrix SD-WAN WANOP Edition 11.3.2a and later releases of 11.3
Citrix SD-WAN WANOP Edition 11.2.3b and later releases of 11.2
Citrix SD-WAN WANOP Edition 10.2.9b and later releases of 10.2

The following supported versions of Citrix ADC and Citrix Gateway address CVE-2021-22920

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1

The following supported versions of Citrix ADC and Citrix Gateway address CVE-2021-22927

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1
Citrix ADC and NetScaler Gateway 11.1-65.22 and later releases of 11.1
Citrix ADC 12.1-FIPS 12.1-55.247 and later releases of 12.1-FIPS

Citrix strongly recommends that affected customers install relevant updates as soon as possible.

If Citrix ADC or Citrix Gateway is configured as a SAML SP, customers must ensure that the device is configured accordingly. See Citrix Application Delivery Controller and Gateway - SAML Configuration Reference Guide for details. Customers who have previously set the SAML configuration according to the document do not need to reapply the configuration changes.

Acknowledgements

Citrix would like to thank Wolfgang Ettlinger and Marc Nimmerrichter of Certitude Consulting for working with us to protect Citrix customers. 

What Citrix is Doing

Citrix is notifying customers and channel partners about this potential security issue through the publication of this security bulletin on the Citrix Knowledge Center at https://support.citrix.com/securitybulletins.

Obtaining Support on This Issue

If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at https://www.citrix.com/support/open-a-support-case.

Subscribe to Receive Alerts

Citrix strongly recommends that all customers subscribe to receive alerts when a Citrix security bulletin is created or modified at https://support.citrix.com/user/alerts.

Reporting Security Vulnerabilities to Citrix

Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to Citrix, please see the following webpage: https://www.citrix.com/about/trust-center/vulnerability-process.html.

Disclaimer

This document is provided on an "as is" basis and does not imply any kind of guarantee or warranty, including the warranties of merchantability or fitness for a particular use. Your use of the information on the document is at your own risk. Citrix reserves the right to change or update this document at any time. Customers are therefore recommended to always view the latest version of this document directly from the Citrix Knowledge Center.

Changelog

Date	Change
2021-07-19	Initial Publication
2021-07-19	CVE-2021-22919 clarification

Citrix Application Delivery Controller, Citrix Gateway, and Citrix SD-WAN WANOP Edition appliance Security Update

Description of Problem

What Customers Should Do

Acknowledgements

What Citrix is Doing

Obtaining Support on This Issue

Subscribe to Receive Alerts

Reporting Security Vulnerabilities to Citrix

Disclaimer

Changelog

Vulmon Search

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