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R2Northstar / NorthstarLauncher

Launcher used to modify Titanfall 2 to allow mods to be loaded
MIT License
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Restricting client commands breaks vanilla compatibility. #214

Open GeckoEidechse opened 2 years ago

GeckoEidechse commented 2 years ago

Unlike vanilla, gameservers in Northstar are considered "untrusted". As such we have to vet commands sent to client by server.

When fixed our previously broken client command restriction with https://github.com/R2Northstar/NorthstarLauncher/pull/210 we also broke vanilla compatibility again.

In particular it breaks matchmaking as (it seems that) when finding a match the server sends a client command to client that causes it to connect to that game server.

Adding -norestrictservercommands should allow matchmaking in vanilla at the cost of reduced security due to allowing server to run commands on client.

If you're using Northstar to play on vanilla and Northstar servers, it's recommended to deleting -norestrictservercommands when playing on Northstar servers.

rolelessweapon commented 2 years ago

It appears this could be due to the "migrateme" command being blocked, which I've fixed in my PR. #189

GeckoEidechse commented 2 years ago

I'm not sure if we do want to allow it though. Cause it could allow an attacker to move you onto a different server. That being said, if an attacker is able to execute that command they likely already have some way of getting ClientCommands to run on your client.

rolelessweapon commented 2 years ago

Couldn't they just run connect?

GeckoEidechse commented 2 years ago

Couldn't they just run connect?

Nope, we block that.

rolelessweapon commented 2 years ago

Actually, it appears migrateme is forwarded from the client to the server. So for some reason, the server (or maybe some internal code in the client that passes the wrong argume to CBuf_AddText) generates the migrateme command, executes it on the client, which then gets forwarded back to the server. Migrateme looks completely harmless.