Vulnerabilities have been discovered in Citrix Gateway and Citrix ADC, listed below. Note that only appliances that are operating as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) are affected by the first issue, which is rated as a Critical severity vulnerability. 

The following supported versions of Citrix ADC and Citrix Gateway are affected by this vulnerability: 

• Citrix ADC and Citrix Gateway 13.1 before 13.1-33.47 

• Citrix ADC and Citrix Gateway 13.0 before 13.0-88.12 

• Citrix ADC and Citrix Gateway 12.1 before 12.1.65.21

• Citrix ADC 12.1-FIPS before 12.1-55.289 

• Citrix ADC 12.1-NDcPP before 12.1-55.289 

This bulletin only applies to customer-managed Citrix ADC and Citrix Gateway appliances. Customers using Citrix-managed cloud services do not need to take any action. 

Instructions

Affected customers of Citrix ADC and Citrix Gateway are recommended to install the relevant updated versions of Citrix ADC or Citrix Gateway as soon as possible: 

• Citrix ADC and Citrix Gateway 13.1-33.47 and later releases 

• Citrix ADC and Citrix Gateway 13.0-88.12 and later releases of 13.0  

• Citrix ADC and Citrix Gateway 12.1-65.21 and later releases of 12.1  

• Citrix ADC 12.1-FIPS 12.1-55.289 and later releases of 12.1-FIPS  

• Citrix ADC 12.1-NDcPP 12.1-55.289 and later releases of 12.1-NDcPP 

Please note that Citrix ADC and Citrix Gateway versions prior to 12.1 are EOL and customers on those versions are recommended to upgrade to one of the supported versions. 

Additionally, and unrelated to the aforementioned CVEs, security enhancements to help protect customers against HTTP Request Smuggling attacks have been added in the above versions of Citrix ADC, and Citrix Gateway. Customers may enable these enhancements using the Citrix ADC management interface. Please see https://support.citrix.com/article/CTX472830 for more information. 

Acknowledgements