https://www.theregister.co.uk/2020/01/20/citrix_patches_vulns_gateway_adc/

Citrix has rushed out official fixes for the well-publicised vuln in some of its server products after miscreants were seen deploying their own custom patches that left a backdoor open for later exploitation.

As previously reported, vulnerabilities in Citrix Application Delivery Encoder and Citrix Gateway could allow remote attackers to carry out unauthenticated code execution.