From 35b2b6df0265e4e0743a0456cfa2c3ec73bbe7da Mon Sep 17 00:00:00 2001 From: Aikar Date: Sat, 2 May 2020 03:09:46 -0400 Subject: [PATCH] Validate PickItem Packet and kick for invalid diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java index 38ec22f4c0..60c3af4d64 100644 --- a/src/main/java/net/minecraft/server/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/PlayerConnection.java @@ -683,7 +683,14 @@ public class PlayerConnection implements PacketListenerPlayIn { @Override public void a(PacketPlayInPickItem packetplayinpickitem) { PlayerConnectionUtils.ensureMainThread(packetplayinpickitem, this, this.player.getWorldServer()); - this.player.inventory.c(packetplayinpickitem.b()); + // Paper start - validate pick item position + if (!(packetplayinpickitem.b() >= 0 && packetplayinpickitem.b() < PlayerInventory.getHotbarSize())) { + PlayerConnection.LOGGER.warn("{} tried to set an invalid carried item", this.player.getDisplayName().getString()); + this.disconnect("Invalid hotbar selection (Hacking?)"); + return; + } + this.player.inventory.c(packetplayinpickitem.b()); // Paper - Diff above if changed + // Paper end this.player.playerConnection.sendPacket(new PacketPlayOutSetSlot(-2, this.player.inventory.itemInHandIndex, this.player.inventory.getItem(this.player.inventory.itemInHandIndex))); this.player.playerConnection.sendPacket(new PacketPlayOutSetSlot(-2, packetplayinpickitem.b(), this.player.inventory.getItem(packetplayinpickitem.b()))); this.player.playerConnection.sendPacket(new PacketPlayOutHeldItemSlot(this.player.inventory.itemInHandIndex)); -- 2.26.2