Patches knowledge book, lectern, painting, and enderman death pot exploits

.gitignore

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+.gradle/
+build/
+.idea/

build.gradle

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+import java.nio.charset.StandardCharsets
+
+plugins {
+    id "java"
+    id "maven-publish"
+    id "net.minecrell.plugin-yml.bukkit" version "0.5.1"
+    id "com.github.johnrengelman.shadow" version "7.1.2"
+    id "io.papermc.paperweight.userdev" version "1.3.4"
+}
+
+repositories {
+    mavenLocal()
+    maven {
+        url = uri("https://papermc.io/repo/repository/maven-public/")
+    }
+
+    maven {
+        url = uri("https://repository.apache.org/content/repositories/snapshots/")
+    }
+
+    maven {
+        url = uri("https://repo.maven.apache.org/maven2/")
+    }
+    mavenCentral()
+}
+
+dependencies {
+    paperweightDevelopmentBundle("io.papermc.paper:dev-bundle:1.18.1-R0.1-SNAPSHOT")
+
+    library 'org.json:json:20211205'
+    library "org.projectlombok:lombok:1.18.22"
+    annotationProcessor "org.projectlombok:lombok:1.18.22"
+}
+
+group = "dev.plex"
+version = "0.1-SNAPSHOT"
+description = "Plex's vulnerability / exploit patcher"
+
+bukkit {
+    name = "Blackout"
+    version = rootProject.version
+    description = "Plex's vulnerability / exploit patcher"
+    main = "dev.plex.Blackout"
+    website = "https://plex.us.org"
+    authors = ["Telesphoreo", "Taah"]
+    apiVersion = "1.18"
+}
+
+java {
+    toolchain.languageVersion.set(JavaLanguageVersion.of(17))
+}
+
+publishing {
+    publications {
+        maven(MavenPublication) {
+            from(components.java)
+        }
+    }
+}
+
+tasks.withType(JavaCompile) {
+    options.encoding = "UTF-8"
+}
+
+reobfJar {
+    setArchivesBaseName("Blackout")
+}
+
+tasks {
+    build {
+        dependsOn(reobfJar)
+    }
+
+    javadoc {
+        options.memberLevel = JavadocMemberLevel.PRIVATE
+    }
+    assemble {
+        dependsOn(reobfJar)
+    }
+
+    compileJava {
+        options.encoding = StandardCharsets.UTF_8.name() // We want UTF-8 for everything
+
+        // Set the release flag. This configures what version bytecode the compiler will emit, as well as what JDK APIs are usable.
+        // See https://openjdk.java.net/jeps/247 for more information.
+        options.release.set(17)
+    }
+    processResources {
+        filteringCharset = StandardCharsets.UTF_8.name() // We want UTF-8 for everything
+    }
+}
+

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.3-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

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+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"

gradlew.bat

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+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

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+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        maven { url("https://papermc.io/repo/repository/maven-public/") }
+    }
+}
+rootProject.name = 'blackout'
+

src/main/java/dev/plex/Blackout.java

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+package dev.plex;
+
+import dev.plex.listener.PlayerListener;
+import dev.plex.packet.PacketManager;
+import dev.plex.packet.impl.EndermanPotionPatch;
+import dev.plex.packet.impl.KnowledgeBookPatch;
+import dev.plex.packet.impl.LecternPatch;
+import dev.plex.packet.impl.PaintingPatch;
+import lombok.Getter;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+import net.minecraft.network.protocol.game.*;
+import org.bukkit.plugin.java.JavaPlugin;
+
+public class Blackout extends JavaPlugin
+{
+    @Getter
+    private static Blackout plugin;
+
+    @Getter
+    private PacketManager packetManager;
+
+    @Override
+    public void onLoad()
+    {
+        plugin = this;
+        debug("Loading");
+    }
+
+    @Override
+    public void onEnable()
+    {
+        this.packetManager = new PacketManager();
+        this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new PaintingPatch());
+        this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new LecternPatch());
+        this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new KnowledgeBookPatch());
+        this.packetManager.registerListener(ClientboundUpdateMobEffectPacket.class, new EndermanPotionPatch());
+
+        this.getServer().getPluginManager().registerEvents(new PlayerListener(), this);
+    }
+
+    public static void debug(String message)
+    {
+        Blackout.getPlugin().getServer().getConsoleSender().sendMessage(Component.text("[Blackout Debug] ").color(NamedTextColor.GOLD).append(LegacyComponentSerializer.legacyAmpersand().deserialize(message)));
+    }
+}

src/main/java/dev/plex/listener/PlayerListener.java

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+package dev.plex.listener;
+
+import dev.plex.util.PacketInterceptorUtil;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
+
+public class PlayerListener implements Listener
+{
+    @EventHandler
+    public void onPlayerJoin(PlayerJoinEvent event)
+    {
+        PacketInterceptorUtil.inject(event.getPlayer());
+    }
+
+    @EventHandler
+    public void onPlayerQuit(PlayerQuitEvent event)
+    {
+        PacketInterceptorUtil.eject(event.getPlayer());
+    }
+}

src/main/java/dev/plex/packet/IPacketListener.java

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+package dev.plex.packet;
+
+import dev.plex.Blackout;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.world.entity.player.Player;
+import org.bukkit.event.Listener;
+
+public interface IPacketListener<T extends Packet<?>> extends Listener
+{
+    default boolean onReceive(Player player, T t)
+    {
+        return true;
+    }
+
+    default Blackout plugin()
+    {
+        return Blackout.getPlugin();
+    }
+}

src/main/java/dev/plex/packet/PacketManager.java

@@ -0,0 +1,36 @@
+package dev.plex.packet;
+
+import com.google.common.collect.Maps;
+import dev.plex.Blackout;
+import lombok.Getter;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.world.entity.player.Player;
+
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class PacketManager
+{
+    @Getter
+    private final Map<Class<? extends Packet<?>>, IPacketListener<Packet<?>>> packetListenerMap = Maps.newHashMap();
+
+    public <T extends Packet<?>> void registerListener(Class<T> clazz, IPacketListener<T> packetListener)
+    {
+        this.packetListenerMap.put(clazz, (IPacketListener<Packet<?>>) packetListener);
+        Blackout.getPlugin().getServer().getPluginManager().registerEvents(packetListener, Blackout.getPlugin());
+    }
+
+    public boolean callPacket(Player player, Packet<?> packet)
+    {
+        AtomicBoolean bool = new AtomicBoolean(true);
+        packetListenerMap.forEach((key, val) -> {
+            if (key.isAssignableFrom(packet.getClass()))
+            {
+                bool.set(val.onReceive(player, packet));
+            }
+        });
+        return bool.get();
+    }
+
+
+}

src/main/java/dev/plex/packet/impl/EndermanPotionPatch.java

@@ -0,0 +1,52 @@
+package dev.plex.packet.impl;
+
+import dev.plex.Blackout;
+import dev.plex.packet.IPacketListener;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.network.protocol.game.ClientboundUpdateMobEffectPacket;
+import net.minecraft.world.effect.MobEffects;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.craftbukkit.v1_18_R1.inventory.CraftItemStack;
+import org.bukkit.entity.EntityType;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.entity.PotionSplashEvent;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class EndermanPotionPatch implements IPacketListener<ClientboundUpdateMobEffectPacket>
+{
+    @EventHandler
+    public void onPotionThrow(PotionSplashEvent event)
+    {
+        if (event.getAffectedEntities().isEmpty()) return;
+        Blackout.debug("Hit entity");
+        if (event.getAffectedEntities().stream().noneMatch(affected -> affected.getType() == EntityType.ENDERMAN)) return;
+        Blackout.debug("Enderman");
+
+        ItemStack item = CraftItemStack.asNMSCopy(event.getPotion().getItem());
+        if (!item.hasTag()) return;
+//        Blackout.debug(item.getTag().getAsString());
+
+        AtomicInteger count = new AtomicInteger();
+
+        Blackout.debug(MobEffects.DAMAGE_BOOST.getDescriptionId());
+        if (!item.getTag().contains("CustomPotionEffects")) return;
+        ListTag tag = (ListTag) item.getTag().get("CustomPotionEffects");
+        tag.forEach(effect -> {
+            CompoundTag compoundTag = (CompoundTag) effect;
+            Blackout.debug(compoundTag.getAsString());
+            if (compoundTag.getByte("Id") == 7)
+            {
+                Blackout.debug("Hi");
+                count.incrementAndGet();
+            }
+        });
+        if (count.get() >= 20)
+        {
+            event.setCancelled(true);
+        }
+    }
+
+
+}

src/main/java/dev/plex/packet/impl/KnowledgeBookPatch.java

@@ -0,0 +1,105 @@
+package dev.plex.packet.impl;
+
+import dev.plex.packet.IPacketListener;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.network.protocol.game.ServerboundUseItemOnPacket;
+import net.minecraft.world.item.ItemStack;
+import org.apache.commons.lang3.EnumUtils;
+import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
+import org.bukkit.craftbukkit.v1_18_R1.inventory.CraftItemStack;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class KnowledgeBookPatch implements IPacketListener<ServerboundUseItemOnPacket>
+{
+    @EventHandler
+    public void onInventoryClick(InventoryClickEvent event)
+    {
+        if (event.getCurrentItem() == null) return;
+
+        org.bukkit.inventory.@Nullable ItemStack bukkitItem = event.getCurrentItem();
+        if (bukkitItem.getType() != Material.KNOWLEDGE_BOOK) return;
+
+        CraftItemStack craftItemStack = (CraftItemStack) bukkitItem;
+        ItemStack item = craftItemStack.handle;
+        if (!item.hasTag()) return;
+        CompoundTag tag = item.getTag();
+        assert tag != null;
+        if (tag.contains("Recipes"))
+        {
+            ListTag recipes = (ListTag) tag.get("Recipes");
+            AtomicBoolean remove = new AtomicBoolean();
+            assert recipes != null;
+            recipes.forEach(recipe -> {
+                if (!recipe.getAsString().startsWith("minecraft:"))
+                {
+                    remove.set(true);
+                    return;
+                }
+                if (NamespacedKey.fromString(recipe.getAsString()) == null)
+                {
+                    remove.set(true);
+                    return;
+                }
+                if (!EnumUtils.isValidEnumIgnoreCase(Material.class, recipe.getAsString().split(":")[1]))
+                {
+                    remove.set(true);
+                }
+            });
+            if (remove.get())
+            {
+                event.getWhoClicked().getInventory().remove(bukkitItem);
+                event.setCancelled(true);
+            }
+        }
+    }
+
+    @EventHandler
+    public void onRightClick(PlayerInteractEvent event)
+    {
+        if (event.getItem() == null) return;
+
+        org.bukkit.inventory.@Nullable ItemStack bukkitItem = event.getItem();
+        if (bukkitItem.getType() != Material.KNOWLEDGE_BOOK) return;
+
+        CraftItemStack craftItemStack = (CraftItemStack) bukkitItem;
+        ItemStack item = craftItemStack.handle;
+        if (!item.hasTag()) return;
+        CompoundTag tag = item.getTag();
+        assert tag != null;
+        if (tag.contains("Recipes"))
+        {
+            ListTag recipes = (ListTag) tag.get("Recipes");
+            AtomicBoolean remove = new AtomicBoolean();
+            assert recipes != null;
+            recipes.forEach(recipe -> {
+                if (!recipe.getAsString().startsWith("minecraft:"))
+                {
+                    remove.set(true);
+                    return;
+                }
+                if (NamespacedKey.fromString(recipe.getAsString()) == null)
+                {
+                    remove.set(true);
+                    return;
+                }
+                if (!EnumUtils.isValidEnumIgnoreCase(Material.class, recipe.getAsString().split(":")[1]))
+                {
+                    remove.set(true);
+                }
+            });
+            if (remove.get())
+            {
+                event.getPlayer().getInventory().remove(bukkitItem);
+                event.setCancelled(true);
+            }
+        }
+    }
+
+}

src/main/java/dev/plex/packet/impl/LecternPatch.java

@@ -0,0 +1,62 @@
+package dev.plex.packet.impl;
+
+import dev.plex.Blackout;
+import dev.plex.packet.IPacketListener;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.network.protocol.game.ServerboundUseItemOnPacket;
+import net.minecraft.world.item.ItemStack;
+import org.apache.commons.lang.StringUtils;
+import org.bukkit.Material;
+import org.bukkit.craftbukkit.v1_18_R1.inventory.CraftItemStack;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class LecternPatch implements IPacketListener<ServerboundUseItemOnPacket>
+{
+    @EventHandler
+    public void onInventoryClick(BlockPlaceEvent event)
+    {
+        ItemStack item = ((CraftItemStack) event.getItemInHand()).handle;
+        Blackout.debug(item.getBukkitStack().getType().name());
+        Blackout.debug(String.valueOf(item.hasTag()));
+        if (item.getBukkitStack().getType() != Material.LECTERN) return;
+        if (!item.hasTag()) return;
+        CompoundTag tag = item.getTag();
+        assert tag != null;
+
+
+        Blackout.debug(StringUtils.join(tag.getAllKeys(), ", "));
+
+        if (!tag.contains("BlockEntityTag")) return;
+        if (!tag.getCompound("BlockEntityTag").contains("Book")) return;
+        if (!tag.getCompound("BlockEntityTag").getCompound("Book").contains("tag")) return;
+        CompoundTag bookTag = tag.getCompound("BlockEntityTag").getCompound("Book").getCompound("tag");
+        ListTag listTag = (ListTag) bookTag.get("pages");
+        assert listTag != null;
+        AtomicInteger integer = new AtomicInteger();
+        listTag.stream().forEach(pageTag ->
+        {
+            JSONArray array = new JSONArray(pageTag.getAsString());
+            array.forEach(obj ->
+            {
+                JSONObject object = new JSONObject(obj.toString());
+                if (!object.isNull("selector") && object.getString("selector").equalsIgnoreCase("@e"))
+                {
+                    integer.getAndIncrement();
+                }
+            });
+        });
+
+        if (integer.get() >= 2)
+        {
+            event.getPlayer().getInventory().remove(item.getBukkitStack());
+            event.setCancelled(true);
+        }
+    }
+
+}

src/main/java/dev/plex/packet/impl/PaintingPatch.java

@@ -0,0 +1,35 @@
+package dev.plex.packet.impl;
+
+import dev.plex.Blackout;
+import dev.plex.packet.IPacketListener;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.Tag;
+import net.minecraft.network.protocol.game.ServerboundUseItemOnPacket;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.Material;
+
+public class PaintingPatch implements IPacketListener<ServerboundUseItemOnPacket>
+{
+    @Override
+    public boolean onReceive(Player player, ServerboundUseItemOnPacket serverboundUseItemOnPacket)
+    {
+        ItemStack item = player.getItemInHand(serverboundUseItemOnPacket.getHand());
+        if (!item.hasTag()) return true;
+        if (item.getBukkitStack().getType() != Material.PAINTING) return true;
+        CompoundTag tag = item.getTag();
+
+        assert tag != null;
+        if (tag.contains("EntityTag", Tag.TAG_COMPOUND))
+        {
+            CompoundTag entityData = tag.getCompound("EntityTag");
+            if (entityData.contains("TileX") || entityData.contains("TileY") || entityData.contains("TileZ"))
+            {
+                Blackout.debug("Applying PAINTING ENTITY TAG PATCH on " + player.getName());
+                player.getInventory().removeItem(item);
+                return false;
+            }
+        }
+        return false;
+    }
+}

src/main/java/dev/plex/util/PacketInterceptorUtil.java

@@ -0,0 +1,37 @@
+package dev.plex.util;
+
+import dev.plex.Blackout;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelDuplexHandler;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import net.minecraft.network.protocol.Packet;
+import org.bukkit.craftbukkit.v1_18_R1.entity.CraftPlayer;
+import org.bukkit.entity.Player;
+
+public class PacketInterceptorUtil
+{
+     public static void inject(Player player) {
+        ChannelDuplexHandler handler = new ChannelDuplexHandler() {
+            @Override
+            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+                if (msg instanceof Packet<?> packet)
+                {
+                    boolean read = Blackout.getPlugin().getPacketManager().callPacket(((CraftPlayer)player).getHandle(), packet);
+                    if (!read) return;
+                }
+                super.channelRead(ctx, msg);
+            }
+        };
+
+        ChannelPipeline pipeline = ((CraftPlayer) player).getHandle().connection.connection.channel.pipeline();
+        pipeline.addBefore("packet_handler", player.getName(), handler);
+    }
+
+    public static void eject(Player player) {
+        Channel channel = ((CraftPlayer) player).getHandle().connection.connection.channel;
+        channel.eventLoop().submit(() -> {
+            channel.pipeline().remove(player.getName());
+        });
+    }
+}