Netscaler recently published a KB describing the impact of CVE-2019-19781 - click here to read more.
The vulnerability allows a hacker to remotely execute code on your ADC appliance. This is a significant vulnerability, pretty much the worst case scenario for any exploit. It is very important that you follow the mitigation steps outlined in the KB from citrix.
The mitigation steps provide a temporary way to stop new exploitation of the platform, and they have a some things you can check to see if you have been compromised. These steps can be found here.
Citrix has planned to release updates to the code, resolving the issue, and as of today, have released fixes for 2 versions of code. If your version is on the list be sure to upgrade ASAP.
Good luck everyone!
SnowCap Leadership Team