A vulnerability has been discovered in Citrix Gateway and Citrix ADC, listed below, that, if exploited, could allow an unauthenticated remote attacker to perform arbitrary code execution on the appliance. 

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

• Citrix ADC and Citrix Gateway 13.0 before 13.0-58.32 

• Citrix ADC and Citrix Gateway 12.1 before 12.1-65.25 

• Citrix ADC 12.1-FIPS before 12.1-55.291 

• Citrix ADC 12.1-NDcPP before 12.1-55.291 

Citrix ADC and Citrix Gateway version 13.1 is unaffected. 

Customers can determine if their Citrix ADC or Citrix Gateway is configured as a SAML SP or a SAML IdP by inspecting the ns.conf file for the following commands: 

• add authentication samlAction

  - Appliance is configured as a SAML SP 

             OR 

• add authentication samlIdPProfile

  - Appliance is configured as a SAML IdP 

If either of the commands are present in the ns.conf file and if the version is an affected version, then the appliance must be updated. 

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

Citrix has also published a related blog at https://www.citrix.com/blogs/2022/12/13/critical-security-update-now-available-for-citrix-adc-citrix-gateway/ , which contains further context.

Instructions

Exploits of this issue on unmitigated appliances in the wild have been reported. Citrix strongly urges affected customers of Citrix ADC and Citrix Gateway to install the relevant updated versions of Citrix ADC or Citrix Gateway as soon as possible: 

• Citrix ADC and Citrix Gateway 13.0-58.32 and later releases 

• Citrix ADC and Citrix Gateway 12.1-65.25 and later releases of 12.1 

• Citrix ADC 12.1-FIPS 12.1-55.291 and later releases of 12.1-FIPS  

• Citrix ADC 12.1-NDcPP 12.1-55.291 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. 

Citrix has also published a related blog at https://www.citrix.com/blogs/2022/12/13/critical-security-update-now-available-for-citrix-adc-citrix-gateway/ , which contains further context