Firefox is using ultrasurf browsing blocked by firewall (Firepower)
After a recent upgrade, i noticed that i can't browse to certain website using firefox, however if I used chrome or any other browser it i can.
after troubleshooting, noticed that in firepower (firewall I am using), the requests are using "ultrasurf client" image attached. Thus application gets blocked.
Made sure I don't have any "ultrasurf" plugin / addon installed, I even tested with running firefox in safemode but still same issue.
I also noticed that when I try to load a site, the connection doesn't go to that website IP but to one of cloudflare IPs. DOH is disabled, I and blocked all Cloudflare connections on the firewall.
Has anyone noticed this with their firefox ?
Version 86 DOH Disabled Firepower detects Ultrasurf client Connections are made to Cloudflare ips (Specifically to the range 220.127.116.11/12)