From c3443175e73aa6cb48534f51f7f11d066f1baf59 Mon Sep 17 00:00:00 2001
From: Dreeam <61569423+Dreeam-qwq@users.noreply.github.com>
Date: Thu, 28 Mar 2024 14:05:58 -0400
Subject: [PATCH] Block log4j rce exploit in chat

---
 ...0080-Block-log4j-rce-exploit-in-chat.patch | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 patches/server/0080-Block-log4j-rce-exploit-in-chat.patch

diff --git a/patches/server/0080-Block-log4j-rce-exploit-in-chat.patch b/patches/server/0080-Block-log4j-rce-exploit-in-chat.patch
new file mode 100644
index 00000000..49a387f3
--- /dev/null
+++ b/patches/server/0080-Block-log4j-rce-exploit-in-chat.patch
@@ -0,0 +1,49 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Dreeam <61569423+Dreeam-qwq@users.noreply.github.com>
+Date: Sat, 9 Mar 2024 10:54:59 -0500
+Subject: [PATCH] Block log4j rce exploit in chat
+
+
+diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+index bf14f2a0eef3d3964d4ce1f09473e5106f20ebb8..0cbfa34b5750bb253a51ffdf19ff76301927aeae 100644
+--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
++++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+@@ -2234,6 +2234,9 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
+             return;
+         }
+         // CraftBukkit end
++
++        if (ServerGamePacketListenerImpl.isLog4jExploit(packet.message())) return; // Leaf - Block log4j rce exploit in chat
++
+         if (ServerGamePacketListenerImpl.isChatMessageIllegal(packet.message())) {
+             this.disconnect(Component.translatable("multiplayer.disconnect.illegal_characters"), org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_CHARACTERS); // Paper - add cause
+         } else {
+@@ -2409,6 +2412,15 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
+         }
+     }
+ 
++    // Leaf start - Block log4j rce exploit in chat
++    public static boolean isLog4jExploit(String message) {
++        java.util.regex.Pattern pattern = java.util.regex.Pattern.compile(".*\\$\\{[^}]*}.*");
++        java.util.regex.Matcher matcher = pattern.matcher(message);
++
++        return matcher.find();
++    }
++    // Leaf end
++
+     public static boolean isChatMessageIllegal(String message) {
+         for (int i = 0; i < message.length(); ++i) {
+             if (!SharedConstants.isAllowedChatCharacter(message.charAt(i))) {
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+index 80ce7779fc2437444ea16db3d09250f82cef0ed5..4eda6d6f6e9fc34852d4b32a26c4f5a564a28f5d 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+@@ -670,6 +670,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
+ 
+         if (this.getHandle().connection == null) return;
+ 
++        if (ServerGamePacketListenerImpl.isLog4jExploit(msg)) return; // Leaf - Block log4j rce exploit in chat
++
+         // Paper start - Improve chat handling
+         if (ServerGamePacketListenerImpl.isChatMessageIllegal(msg)) {
+             this.getHandle().connection.disconnect(Component.translatable("multiplayer.disconnect.illegal_characters"), org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_CHARACTERS); // Paper - kick event causes