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/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java index b1aaf19df210fa98910d49535e56f5b26c72d26f..14ae626be2ff07640e66bad5e6e538da8cadaf7b 100644 --- a/src/main/java/net/minecraft/server/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/PlayerConnection.java @@ -1092,6 +1092,11 @@ 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();