From e4a35d4d710e5781cb384e3ad08309f43c0f4b44 Mon Sep 17 00:00:00 2001
From: PermisosDev <55111245+PermisosDev@users.noreply.github.com>
Date: Thu, 15 Apr 2021 08:34:57 -0300
Subject: [PATCH] Check if packetID is invalid.


diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java b/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
index dd089abd..b3de7a7b 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
@@ -65,7 +65,10 @@ public class MinecraftDecoder extends MessageToMessageDecoder<ByteBuf>
 
             int packetId = DefinedPacket.readVarInt( in );
             packetTypeInfo = packetId;
-
+            // FlameCord Start - Check if packetId is invalid.
+            if (packetId < 0 || packetId > Protocol.MAX_PACKET_ID)
+                throw new BadPacketException("[" + ctx.channel().remoteAddress() + "] <-> MinecraftDecoder received invalid packet #1, id " + packetId);
+            // Flamecord End
             DefinedPacket packet = prot.createPacket( packetId, protocolVersion, supportsForge );
             if ( packet != null )
             {
-- 
2.29.2.windows.3