detecting Meteor Client via a sign-based check

[SNOWLLYY]

Describe the bug

DonutSMP is detecting Meteor Client via a sign-based check. When a specially crafted sign is edited, the client sends an UpdateSignC2SPacket. On vanilla clients, certain text values remain unresolved, but Meteor resolves them differently.

The server compares the received text and detects Meteor usage based on this difference. This results in bans even if the client isn’t actively used.

This detection method may cause false positives and should be reviewed or mitigated.

Steps to reproduce

1. joined the server
2. sign appeared on the player head
3. player got banned

Meteor Version

1.21

Minecraft Version

1.21

Operating System

Windows

Before submitting a bug report

• This bug wasn't already reported (I have searched bug reports on GitHub).

• This is a valid bug (I am able to reproduce this on the latest dev build).

[github-actions]

This issue is being automatically closed.

Meteor is intended to be used as a utility client on servers that explicitly allow its use. We do not intend to add workarounds for specific anticheats unless it falls within that scope.

This issue was closed because you used the term "donut". If you believe your issue is not associated with the given reason you may reopen it.

[crosby-moe]

using meteor on donutsmp is not supported

[SNOWLLYY]

is there a way i could disable that issue cause i don't seem to find any good alternative that has proxy support and some futures like unfocused cpu

[SNOWLLYY]

any packets in meteor that could send data to the server that there meteor client beside update sign? just wanna make sure there no other ways so i can prevent any bad new to happen to my account

[SNOWLLYY]

Hey if packet cancelation the server won;t receive anything not even a vanilla text and that could case the server to know the this client is hiding am i right ?

[PedroMPagani]

Yes snowllyy. we know you're not answering to teh packet.
We do not support meteor client, it's against our rules and terms of service. just simply stop ;)