[reflexe]

Maybe i am missing something but while it is interesting, I dont think it has any real security impact.

Since the threat model is that the attacker and the victim are connected to the same router via the same wifi network, not isolated from each other, in a case where you are using wifi in psk for example, the attacker can already sniff everything from other clients.

Therefore, you can spoof packets by just responding to them directly. It is a lot simpler and takes a lot less time (since you just need to respond faster than the server with the right seq and port numbers). Once you are in the same network you can do even crazier stuff like arp spoofing and then let the victim think that you are the router and convince it to send all of its packets to you (https://en.m.wikipedia.org/wiki/ARP_spoofing)

Edit: on a second thought, maybe in a use case where the victim and the attacker are in different wifi networks (or just configured to be isolated ), the attacker should be able to perform a denial of service for a specific ip:port by sending RST and then ACK with every possible source port.

[vass77]

Also only works with non encrypted conns (ftp, http), that one should not be using. And like you say on open or PSK networks you can do worst stuff (if isolation is not enable arp spoofing the default G will be way worst then this)