"Oversized" Sign exploit patched

gradle.properties

@@ -1,2 +1,2 @@
 pluginGroup=me.cooljwb.vulnerabilitypatcher
-pluginVersion=v1.9.3.1
+pluginVersion=v1.9.4

src/main/java/me/cooljwb/vulnerabilitypatcher/VulnerabilityPatcher.java

@@ -193,6 +193,9 @@ public final class VulnerabilityPatcher extends JavaPlugin
                 case "ItemNames":
                     listeners.add(new Item_Names());
                     break;
+                case "OversizedSigns":
+                    listeners.add(new Oversized_Sign());
+                    break;
             } // Adds all events to the event register.
         }
         listeners.forEach(listener -> Bukkit.getPluginManager().registerEvents(listener, this)); // Register the events.

src/main/java/me/cooljwb/vulnerabilitypatcher/commands/CommandGetNBT.java

@@ -31,9 +31,9 @@ public class CommandGetNBT extends Patches implements CommandExecutor
             ItemStack item = player.getInventory().getItemInMainHand();
             String strItem = itemToString(item);
 
-            if (item != null && item.getType() != Material.AIR && strItem != null && !(strItem.length() > 5000))
+            if (item.getType() != Material.AIR && strItem != null && !(strItem.length() > 5000))
                 msg(sender, SMG.VULNERABILITYPATCHER.msg + ChatColor.GRAY + "Item data: " + ChatColor.GREEN + ChatColor.stripColor(strItem));
-            else if (item == null || item.getType() == Material.AIR)
+            else if (item.getType() == Material.AIR)
                 msg(sender, SMG.GET_ITEM_IN_MAINHAND.msg);
             else if (strItem == null)
                 msg(sender, SMG.NO_TAG.msg);

src/main/java/me/cooljwb/vulnerabilitypatcher/modifiers/NBTModifier.java

@@ -5,6 +5,7 @@ import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Firework;
 import org.bukkit.entity.Player;
+import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.SpawnEggMeta;
 import org.bukkit.projectiles.ProjectileSource;
@@ -489,4 +490,21 @@ public class NBTModifier
         }
         return false;
     }
+
+    protected boolean isOversizedSign(ItemStack item)
+    {
+        if (getVersion().equals("1.16.5"))
+        {
+            return nbt_1_16_3.isOversizedSign(item);
+        }
+        return false;
+    }
+
+    protected void clearOversizedSign(BlockPlaceEvent event)
+    {
+        if (getVersion().equals("1.16.5"))
+        {
+            nbt_1_16_3.clearOversizedSign(event);
+        }
+    }
 }

src/main/java/me/cooljwb/vulnerabilitypatcher/modifiers/NBTModifier_1_16_3.java

@@ -19,6 +19,7 @@ import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Firework;
 import org.bukkit.entity.Player;
+import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
 import org.bukkit.inventory.meta.SpawnEggMeta;
@@ -500,4 +501,55 @@ public class NBTModifier_1_16_3
         }
         return false;
     }
+
+    boolean isOversizedSign(ItemStack item)
+    {
+        if (item != null && item.getType().name().contains("SIGN"))
+        {
+            net.minecraft.server.v1_16_R3.ItemStack nmsItem = CraftItemStack.asNMSCopy(item);
+            NBTTagCompound tag = nmsItem.getTag().getCompound("BlockEntityTag");
+            String text1 = tag.getString("Text1").toLowerCase();
+            String text2 = tag.getString("Text2").toLowerCase();
+            String text3 = tag.getString("Text3").toLowerCase();
+            String text4 = tag.getString("Text4").toLowerCase();
+            return text1.contains("\"nbt\":") || text2.contains("\"nbt\":") || text3.contains("\"nbt\":") || text4.contains("\"nbt\":");
+        }
+        return false;
+    }
+
+    void clearOversizedSign(BlockPlaceEvent event)
+    {
+        ItemStack item = event.getItemInHand();
+        net.minecraft.server.v1_16_R3.ItemStack nmsItem = CraftItemStack.asNMSCopy(item);
+        NBTTagCompound tag = nmsItem.getTag().getCompound("BlockEntityTag");
+        String text1 = tag.getString("Text1").toLowerCase();
+        String text2 = tag.getString("Text2").toLowerCase();
+        String text3 = tag.getString("Text3").toLowerCase();
+        String text4 = tag.getString("Text4").toLowerCase();
+        if (text1.contains("\"nbt\":"))
+        {
+            tag.setString("Text1", "{\"text\":\"NBT tag removed\"}");
+        }
+        if (text2.contains("\"nbt\":"))
+        {
+            tag.setString("Text2", "{\"text\":\"NBT tag removed\"}");
+        }
+        if (text3.contains("\"nbt\":"))
+        {
+            tag.setString("Text3", "{\"text\":\"NBT tag removed\"}");
+        }
+        if (text4.contains("\"nbt\":"))
+        {
+            tag.setString("Text4", "{\"text\":\"NBT tag removed\"}");
+        }
+        ItemStack newItem = CraftItemStack.asBukkitCopy(nmsItem);
+        if (event.getPlayer().getInventory().getItemInMainHand().equals(item))
+        {
+            event.getPlayer().getInventory().setItemInMainHand(newItem);
+        }
+        else
+        {
+            event.getPlayer().getInventory().setItemInOffHand(newItem);
+        }
+    }
 }

src/main/java/me/cooljwb/vulnerabilitypatcher/patches/Entity_Tag.java

@@ -54,24 +54,21 @@ public class Entity_Tag extends Patches implements Listener
     {
         ItemStack item = event.getItem();
 
-        if (item != null)
+        if (isDangerousEgg(item))
         {
-            if (isDangerousEgg(item))
+            event.setCancelled(true);
+            Container container = (Container) event.getBlock().getState();
+
+            for (int c = 0; c < container.getInventory().getSize(); c++)
             {
-                event.setCancelled(true);
+                if (container.getInventory().getItem(c) != null)
-                Container container = (Container) event.getBlock().getState();
-
-                for (int c = 0; c < container.getInventory().getSize(); c++)
                 {
-                    if (container.getInventory().getItem(c) != null)
+                    if (container.getInventory().getItem(c).isSimilar(event.getItem()))
-                    {
+                        container.getInventory().getItem(c).setItemMeta(null);
-                        if (container.getInventory().getItem(c).isSimilar(event.getItem()))
-                            container.getInventory().getItem(c).setItemMeta(null);
-                    }
                 }
-
-                notifyViolation(event.getBlock().getType().name(), "use", "dangerous mob egg", event.getBlock().getLocation());
             }
+
+            notifyViolation(event.getBlock().getType().name(), "use", "dangerous mob egg", event.getBlock().getLocation());
         }
 
         debug(event);

src/main/java/me/cooljwb/vulnerabilitypatcher/patches/Oversized_Sign.java

@@ -0,0 +1,22 @@
+package me.cooljwb.vulnerabilitypatcher.patches;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.BlockPlaceEvent;
+
+public class Oversized_Sign extends Patches implements Listener
+{
+
+    @EventHandler(priority = EventPriority.HIGHEST)
+    public void onBlockPlace(BlockPlaceEvent event)
+    {
+        if (isOversizedSign(event.getItemInHand()))
+        {
+            event.setCancelled(true);
+            clearOversizedSign(event);
+            notifyViolation(event.getPlayer(), "place", "oversized sign", event.getBlock().getLocation());
+        }
+        debug(event);
+    }
+}

src/main/java/me/cooljwb/vulnerabilitypatcher/patches/Patches.java

@@ -124,7 +124,8 @@ public class Patches extends NBTModifier implements Listener
                         {
                             if (item != null && item.getItemMeta() != null)
                             {
-                                if (item.getItemMeta().getEnchants() != null && !item.getItemMeta().getEnchants().isEmpty())
+                                item.getItemMeta().getEnchants();
+                                if (!item.getItemMeta().getEnchants().isEmpty())
                                 {
                                     for (Map.Entry entry : item.getItemMeta().getEnchants().entrySet())
                                     {
@@ -328,7 +329,7 @@ public class Patches extends NBTModifier implements Listener
         ItemStack mainhand = inv.getItemInMainHand();
         ItemStack offhand = inv.getItemInOffHand();
 
-        if (item != null && inv != null && mainhand != null && offhand != null)
+        if (item != null)
         {
             if (inv.getItemInMainHand().isSimilar(item) || inv.getItemInOffHand().isSimilar(item))
                 return true;

src/main/resources/config.yml

@@ -24,6 +24,7 @@ Patches:
   - Beehives # Removes all NBT data from any EntityBlockStorage such as beehives
   - Skulls # Purges empty skull owner IDs
   - ItemNames # Removes item names with events in them.
+  - OversizedSigns # Removes signs with NBT tag
 
 # All entities added below will be blocked to use in a spawn egg.
 BlockedEntityTags:

src/main/resources/plugin.yml

@@ -1,5 +1,5 @@
 name: VulnerabilityPatcher
-version: "1.9.3.1"
+version: "1.9.4"
 api-version: 1.13
 main: me.cooljwb.vulnerabilitypatcher.VulnerabilityPatcher
 authors: [CoolJWB]