AnarchyExploitFixes: Protecting Your Minecraft Server From Packet Exploits

Running a truly lawless Minecraft anarchy server sounds fun until someone crashes the entire world with a crafted packet, duplicates infinite resources, or spawns 10,000 mobs to lag you offline. AnarchyExploitFixes is a Paper plugin that blocks the most common ways players wreck anarchy servers, so you can actually keep the chaos contained.

What This Plugin Does

AnarchyExploitFixes stops packet-based attacks and hacked item exploits that plague anarchy servers. Instead of preventing every action (like vanilla anti-cheat), it specifically targets the vectors that cause server crashes, infinite duplication, and game-breaking mechanics. Written in Java with over 400 stars on GitHub, it's become standard protection on servers ranging from tiny test realms to high-traffic anarchies.

The plugin works by intercepting malformed packets before they reach the server's core systems. Players can still perform legitimate actions, but the ones that bypass normal game rules get blocked. Think of it as a bouncer that knows exactly which sketches are actually harmful.

Why Anarchy Servers Get Destroyed Without It

In a typical survival server, you're protected by permission systems and moderators. Anarchy servers intentionally remove that - no moderators, no rules, everyone plays raw. That freedom is the whole appeal. But it also means someone can craft a packet that dupes diamonds infinitely, crashes the server entirely, or locks up chunks so nobody can build there.

Without exploit protection, anarchy servers tend to last about three weeks before they become unplayable. With it? Some of the servers listed in AnarchyExploitFixes' directory (like constantiam.net) have been running for years. You're not making anarchy less anarchic - you're just removing the specific methods that trivialize survival.

And that matters if you want pvp, building, and resource competition to actually mean something.

Installation: What You Need

First, the boring requirements: your server needs to be running Paper (a Minecraft server fork), and you'll need the PacketEvents library installed separately. PacketEvents is a dependency - AnarchyExploitFixes can't run without it, so grab that first from the PacketEvents GitHub repository.

Once you've both.jar files:

1. Place both PacketEvents.jar and AnarchyExploitFixes.jar into your server's plugins/ folder
2. Restart the server
3. Edit the config file that appears in plugins/AnarchyExploitFixes/
4. Restart again to apply your settings

Downloads are available from Modrinth or the GitHub releases page. The plugin maintains separate builds for modern servers (1.20.6+) and legacy versions (1.12.2-1.19.4), so grab the version that matches your server.

cd /path/to/server/plugins
wget https://modrinth.com/plugin/anarchyexploitfixes/version/2.7.12-Modern # Modern servers
cd.../stop.sh
java -Xmx30G -Xms30G -jar paper.jar nogui # restart

After the first start, check the logs. If you see errors about PacketEvents not being found, you haven't installed the dependency correctly.

What It Protects Against

The plugin blocks several categories of exploits, and the latest version (2.7.12) added some new ones. Here's what actually matters:

Packet-based crashes: Certain packet sequences cause server hangs or instant shutdowns. AnarchyExploitFixes catches these before they propagate.

NBT (Named Binary Tag) exploits: Items with impossible data - infinite enchantments, negative damage values, ridiculous lore size - get filtered out. This prevents duping and certain crash vectors.

Bundle exploits: A recent addition that stops clients from crashing servers using the bundle mechanic.

Illegal DataComponent items: Minecraft 1.20+ uses DataComponents instead of NBT for some data. The plugin checks those too.

Chat spam and ping flooding: Basic denial-of-service attempts through chat or ping packets.

One thing to know upfront: this doesn't catch everything. The README mentions that some exploits are already handled by other plugins like LPX AntiPacketExploit or Panilla. You might want to run multiple anti-exploit tools if you're paranoid (and if you're running an anarchy server at scale, you probably should be).

Configuration and What You'll Probably Change

The config file is extensive. Most servers leave most options at defaults, but a few tweaks matter.

By default, AnarchyExploitFixes logs every blocked exploit attempt. On a high-player server, that's thousands of log lines per hour and can slow down your logs. Consider disabling debug output unless you're actively investigating something.

You can disable specific modules if they cause issues with custom plugins or legitimate playstyles you want to support. For example, if your players legitimately use special enchantment systems, you might soften NBT filtering. But be careful - every rule you disable is a potential attack vector.

The "first join messages" setting got its own toggle in version 2.7.12, which is nice if you prefer not to spam new players with anti-exploit notifications.

Gotchas and What Trips People Up

One of the biggest mistakes: forgetting that PacketEvents needs to be installed as a separate plugin. You'll place the jar in plugins/, restart, and see error messages about PacketEvents being missing. It's not the plugin's fault - you just skipped a step.

Performance-wise, AnarchyExploitFixes is designed to be lightweight, but on a server with hundreds of concurrent players, every packet inspection has overhead. The changelog for 2.7.12 mentions performance improvements across various modules, so if you're on an older version, update. A latest release also dropped NBT-API shading (previously the plugin bundled its own copy), which cuts load times and reduces conflicts with other plugins.

If you're running an old Paper version (pre-1.20), compatibility can get weird. Stick to the Legacy build if you're on 1.19.4 or below.

How It Compares to Alternatives

LPX AntiPacketExploit is more focused and catches a narrower set of exploits, making it faster but less full. Panilla specializes in hacked items specifically. Most anarchy servers with serious uptimes use at least one of these alongside AnarchyExploitFixes because they catch different things. There's no "one plugin does it all" approach to anarchy security.

AnarchyExploitFixes stands out for being actively maintained (the 2.7.12 release supports Minecraft through 1.21.8), highly configurable, and open-source so you can see exactly what it's doing.

Tools Worth Pairing With This

If you're setting up an anarchy server, you'll also want to monitor your server's health. Use our Minecraft Server Status Checker to verify players can actually connect when you think they can, especially after applying security updates. It's a quick sanity check that saves you from silent connectivity issues.

And if you're documenting your server (custom rules, whitelist, server message), the Minecraft MOTD Creator lets you build a server greeting that stands out in the server list without needing to touch YAML files.

Ready to try AnarchyExploitFixes?

Grab the source, read the full documentation, or open an issue on GitHub. Star the repo if you find it useful. It helps the maintainers and surfaces the project for other Minecraft players.