Paper/patches/server/0713-Add-root-admin-user-detection.patch
Jake Potrebic 90fe0d58a5
Updated Upstream (Bukkit/CraftBukkit/Spigot) (#9825)
Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
897a0a23 SPIGOT-5753: Back PotionType by a minecraft registry
255b2aa1 SPIGOT-7080: Add World#locateNearestBiome
ff984826 Remove javadoc.io doc links

CraftBukkit Changes:
71b0135cc SPIGOT-5753: Back PotionType by a minecraft registry
a6bcb8489 SPIGOT-7080: Add World#locateNearestBiome
ad0e57434 SPIGOT-7502: CraftMetaItem - cannot deserialize BlockStateTag
b3efca57a SPIGOT-6400: Use Mockito instead of InvocationHandler
38c599f9d PR-1272: Only allow one entity in CraftItem instead of two
f065271ac SPIGOT-7498: ChunkSnapshot.getBlockEmittedLight() gets 64 blocks upper in Overworld

Spigot Changes:
e0e223fe Remove javadoc.io doc links
2023-10-22 20:12:00 +01:00

80 lines
4.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: egg82 <eggys82@gmail.com>
Date: Sat, 11 Sep 2021 22:55:14 +0200
Subject: [PATCH] Add root/admin user detection
This patch detects whether or not the server is currently executing as a privileged user and spits out a warning.
The warning serves as a sort-of PSA for newer server admins who don't understand the risks of running as root.
We've seen plenty of bad/malicious plugins hit markets, and there's been a few close-calls with exploits in the past.
Hopefully this helps mitigate some potential damage to servers, even if it is just a warning.
Co-authored-by: Noah van der Aa <ndvdaa@gmail.com>
diff --git a/src/main/java/io/papermc/paper/util/ServerEnvironment.java b/src/main/java/io/papermc/paper/util/ServerEnvironment.java
new file mode 100644
index 0000000000000000000000000000000000000000..6bd0afddbcc461149dfe9a5c7a86fff6ea13a5f1
--- /dev/null
+++ b/src/main/java/io/papermc/paper/util/ServerEnvironment.java
@@ -0,0 +1,40 @@
+package io.papermc.paper.util;
+
+import com.sun.security.auth.module.NTSystem;
+import com.sun.security.auth.module.UnixSystem;
+import org.apache.commons.lang.SystemUtils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Set;
+
+public class ServerEnvironment {
+ private static final boolean RUNNING_AS_ROOT_OR_ADMIN;
+ private static final String WINDOWS_HIGH_INTEGRITY_LEVEL = "S-1-16-12288";
+
+ static {
+ if (SystemUtils.IS_OS_WINDOWS) {
+ RUNNING_AS_ROOT_OR_ADMIN = Set.of(new NTSystem().getGroupIDs()).contains(WINDOWS_HIGH_INTEGRITY_LEVEL);
+ } else {
+ boolean isRunningAsRoot = false;
+ if (new UnixSystem().getUid() == 0) {
+ // Due to an OpenJDK bug (https://bugs.openjdk.java.net/browse/JDK-8274721), UnixSystem#getUid incorrectly
+ // returns 0 when the user doesn't have a username. Because of this, we'll have to double-check if the user ID is
+ // actually 0 by running the id -u command.
+ try {
+ Process process = new ProcessBuilder("id", "-u").start();
+ process.waitFor();
+ InputStream inputStream = process.getInputStream();
+ isRunningAsRoot = new String(inputStream.readAllBytes()).trim().equals("0");
+ } catch (InterruptedException | IOException ignored) {
+ isRunningAsRoot = false;
+ }
+ }
+ RUNNING_AS_ROOT_OR_ADMIN = isRunningAsRoot;
+ }
+ }
+
+ public static boolean userIsRootOrAdmin() {
+ return RUNNING_AS_ROOT_OR_ADMIN;
+ }
+}
diff --git a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
index b9a4447e790f34fd8f88f353bf0e24a18a298ee6..c7894892afe97eb3cb453c37a2d9a23d811d70b8 100644
--- a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
@@ -179,6 +179,16 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
DedicatedServer.LOGGER.warn("To start the server with more ram, launch it as \"java -Xmx1024M -Xms1024M -jar minecraft_server.jar\"");
}
+ // Paper start - detect running as root
+ if (io.papermc.paper.util.ServerEnvironment.userIsRootOrAdmin()) {
+ DedicatedServer.LOGGER.warn("****************************");
+ DedicatedServer.LOGGER.warn("YOU ARE RUNNING THIS SERVER AS AN ADMINISTRATIVE OR ROOT USER. THIS IS NOT ADVISED.");
+ DedicatedServer.LOGGER.warn("YOU ARE OPENING YOURSELF UP TO POTENTIAL RISKS WHEN DOING THIS.");
+ DedicatedServer.LOGGER.warn("FOR MORE INFORMATION, SEE https://madelinemiller.dev/blog/root-minecraft-server/");
+ DedicatedServer.LOGGER.warn("****************************");
+ }
+ // Paper end
+
DedicatedServer.LOGGER.info("Loading properties");
DedicatedServerProperties dedicatedserverproperties = this.settings.getProperties();