Comment by tifkap
5 days ago
This is most likely an attempt to connect to a webserver on your own device to collect data and/or do tracking.
Remember back in June when Facebook/meta got caught tracking users trough a webserver on Android phone thought Messenger and Instagram? Same thing.
Why do you say that’s most likely?
This is a common pattern for connecting to smart cards / hardware security devices. Probably a service or hardware that’s run on official CBP machines that should be disabled for prod, but forgot.
This is by far the most likely reason.
I personally use pages that authenticate via a smartcard using this exact scheme.
There is a Java "plugin" that is nothing but a mini webserver that listens on a specific port and performs authentication.
How are you so sure?