Citrix is aware of two recently announced vulnerabilities in Microsoft Windows Print Spooler service (CVE-2021-1675 and CVE-2021-34527, also known as “PrintNightmare”). Whilst these vulnerabilities do not directly affect Citrix products, Citrix customers may be concerned about the impact of applying any workarounds and/or updates to their Citrix environments.

Microsoft has provided temporary workarounds and is also releasing security updates to address the vulnerabilities.

Citrix has not fully tested the temporary workarounds that Microsoft has provided but expects that these workarounds are likely to cause some adverse effects to Citrix users. These include, but are not limited to, problems using Citrix Universal Print Server.

Citrix has performed functional testing of the Microsoft security updates and has not identified an impact to Citrix functionality. However, we will continue to monitor the situation and update this guidance if necessary..