CrashExploitFixer

<h1>CrashExploitFixer</h1> <p>This mod fixes a server crash exploit that has been bandaid-fixed by Mojang in Minecraft 1.21.1, which allows malicious players to crash a server immediately after joining it. It is currently estimated that this exploit is available on all versions back to 1.14.4!</p> <p>If you are interested in the technical details of this exploit I recommend reading <a href="https://haykam.com/blog/entity-selector-stack-overflow-crash" rel="nofollow">haykam's blogpost</a> on the topic.</p>

What Minecraft versions are affected?

All versions between 1.14.4 and 1.21 (inclusive) are confirmed to be affected. The issue was likely introduced in 17w45b, a 1.13 snapshot.

How hard is it to perform the exploit?

There has been some confusion on this. Mojang fixed two crash exploits in 1.21.1! One has been made very popular through a youtube video and has a lot of other cool exploits, but requires A LOT of complicated setup. The other exploit however allows anyone who has access to join a server (no permissions or anything required) to immediately crash it by sending one malicious packet!

I don't know you or your mods, how do I trust you?

I am trying to keep everything as transparent as possible.

• The project is open source and can be inspected on github

• The mod is very small, the entire patch logic lies within one small mixin and implements logic from paper that has already been tested on approximately 100.000 paper servers.

• The mod has already been successfully included in many major modpacks!