How do you know it is avast
When running that test you are testing the first firewall on the network, so the port probe may never reach your computer firewall
Are you behinde a router with firewall, then that is the one that is tested
Is your ISP blocking some ports?
If you turn off avast firewall and windows firewall (windows firewall will be turned on when you turn off avast firewall) in your computer and then run the test, what result do you get then?
It is explainet if you read the info below the scan result
see the chapter: Detecting Ports Blocked by Your ISP
So basically, this port is vulnerable to hacker attacks
That does not mean anyone can come inn .... the door is closed