Hello there, we use a 3rd party company to perform periodic network perimeter scans (Both internal and external).
During their latest audit they flagged the Pritunl Web Portal (Which at the time we had open to the Internet) as possibly being affected by a “TCP/IP Initial Sequence Number (ISN) Reuse Weakness”
As a precaution we blocked access to the web portal from the Internet, which, admittedly you guys do recommend not exposing to the web 
… But it’s so darn convenient now that we have so many WFH users, and we figured that in between having Azure MFA enabled, our firewall’s IPS and geo-blocking, it’s safe enough to have it online.
Anyway, that’s all. Checking to see if this is something we need to worry about.
Thanks.