NINA or Server/Client example code vulnerable to exploit?

This morning I found a clue to why my Arduino Uno Wifi Rev 2 stops responding to http requests after several hours. I’m printing to the serial monitor everything that that comes in from the network. The last thing on the serial monitor is:

new client ← a message from our code which was based on the SimpleWebServerWifi example.
Cookie: mstshash=Administr ← Google says this is a well known RDP hack (string also contains some unprintable characters)

The NINA is running NINA firmware (1.4.1)

Is the NINA firmware 1.4.1 or the wifiNINA Client/Server library code vulnerable to this attack somehow? It looks like it might be.

I haven’t got as far as debugging whether the NINA has stopped responding, or the arduino Wifi client/server side code has fallen into a pit. Our top level code is not doing any fancy protocols, it just prints every character it receives and then responds to a few Get requests. It’s just based on the example simple wifi server code.

Has anyone else seen this?