From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Spottedleaf Date: Fri, 12 Jun 2020 16:51:39 -0700 Subject: [PATCH] Prevent position desync in playerconnection causing tp exploit Caused the server to revert to the player's overworld coordinates after teleporting into the end. Sidenote: The underlying issue is that the move call can teleport entities and do other things like kill the entity. In the future, to fix all exploits derieved from this usually unexpected behaviour, we need to move all of this dangerous logic outside of the move call and into an appropriate place in the tick method. diff --git a/src/main/java/net/minecraft/server/network/PlayerConnection.java b/src/main/java/net/minecraft/server/network/PlayerConnection.java index d8be5ff9620da8d96a0d157fb99145d3b43299df..caabb6c831ba280ef6b74ba8aee94c9c3375f38b 100644 --- a/src/main/java/net/minecraft/server/network/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/network/PlayerConnection.java @@ -1324,6 +1324,11 @@ public class PlayerConnection implements PacketListenerPlayIn { this.player.move(EnumMoveType.PLAYER, new Vec3D(d7, d8, d9)); this.player.setOnGround(packetplayinflying.b()); // CraftBukkit - SPIGOT-5810, SPIGOT-5835: reset by this.player.move + // Paper start - prevent position desync + if (this.teleportPos != null) { + return; // ... thanks Mojang for letting move calls teleport across dimensions. + } + // Paper end - prevent position desync double d12 = d8; d7 = d4 - this.player.locX();