Citrix security advisory

From: Canadian Centre for Cyber Security

Number: AV20-020
Date: 24 January 2020

On 24 January 2020 Citrix released the final security update to address a critical vulnerability, tracked as CVE-2019-19781, for the following products:

  • Citrix ADC and Citrix Gateway version 13.0 all supported builds before 13.0.47.24
  • NetScaler ADC and NetScaler Gateway version 12.1 all supported builds before 12.1.55.18
  • NetScaler ADC and NetScaler Gateway version 12.0 all supported builds before 12.0.63.13
  • NetScaler ADC and NetScaler Gateway version 11.1 all supported builds before 11.1.63.15
  • NetScaler ADC and NetScaler Gateway version 10.5 all supported builds before 10.5.70.12
  • Citrix SD-WAN WANOP appliance models 4000-WO, 4100-WO, 5000-WO, and 5100-WO all supported software release builds before 10.2.6b and 11.0.3b

Successful exploitation of this vulnerability may allow an unauthenticated remote actor to perform arbitrary code execution.

In addition to the above patches, Citrix has released an Indicator of Compromise utility that provides a best effort job at identifying existing compromises of
Citrix appliances related to CVE-2019-19781.

The Cyber Centre encourages users and administrators to review the following Citrix publications and apply the necessary updates:

Citrix Advisory

https://support.citrix.com/article/CTX267027

Mitigation Steps

https://support.citrix.com/article/CTX267679

Citrix Indicator of Compromise utility

https://github.com/citrix/ioc-scanner-CVE-2019-19781/

Note to Readers

The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment.  We are Canada’s national authority on cyber security and we lead the government’s response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure, Canadian businesses and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support, and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.

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