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GrimAnticheat / Grim

Fully async, multithreaded, predictive, open source, 3.01 reach, 1.005 timer, 0.01% speed, 99.99% antikb, "bypassable" 1.8-1.20 anticheat.
GNU General Public License v3.0
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Simulation and AntiKB on cactus damage #1013

Open AlmostSomeone opened 1 year ago

AlmostSomeone commented 1 year ago

Describe the false positive and how to replicate it

Simply scrape against a cactus while walking, like you can see in the video. This is found in the Grim AC test server.

Grim log: https://paste.grim.ac/4ayhJ Video: https://youtu.be/s1DlgfRDSy4

Grim version

2.3.38

Server version

Paper 1.19.4 (git-Paper-457)

Plugins

AnimeBoard, AntiDisconnectSpam, ClearLag, Essentials, EssentialsChat, EssentialsSpawn, GrimAC, LightPerms, MyCommand, PlaceholderAPI, ViaBackwards, ViaRewind, ViaVersion, WorldEdit, WorldGuard

Valyrox commented 1 year ago

What's your client version?

SamB440 commented 1 year ago

What's your client version?

They're on 1.19.4, you can see it on the grim log.

Did some quick testing and was able to reproduce on 1.19.4 and 1.19.3.

I think this is to do with sprinting, because of that 0.02940 offset: https://paste.grim.ac/BVxul

c0dingnoobi commented 1 year ago

Yes this is also reproduceable even on legacy versions as 1.8 as @SamB440 mentioned it is probably related to #838 due to having a similar offset (unless this is reproduceable only with walking, which i wasnt to)

SamB440 commented 1 year ago

Yes this is also reproduceable even on legacy versions as 1.8 as @SamB440 mentioned it is probably related to #838 due to having a similar offset (unless this is reproduceable only with walking, which i wasnt to)

I'm not sure if anything can even be done on Grim's side, it might be Mojang that has to fix these sprint desyncs.

As stated on that issue, I tried to apply a fix whereby if the player attacks whilst sprinting and didn't send a sprint update after, it will tell the server their sprint updated. However, this changes gameplay.

The bug has been on the bug site for almost 10 years now, I doubt it's getting fixed: https://bugs.mojang.com/browse/MC-69459 (this bug is for attacking, but I'm almost certain there are definitely desyncs elsewhere, like this)

As the bug report says:

Any fix for this will change gameplay noticeably. Preserving the client behavior and fixing the server to stay in sync will make sprint knockback much more powerful. Changing the client to match the server means that sprinting will be interrupted when attacking, which players may consider regressive.