4 ms·

If anyone else was lost like myself, here is the rundown. The linked github readme assumes prior knowledge of 2b2t. This is an exploit for a very old Minecraft

If anyone else was lost like myself, here is the rundown. The linked github readme assumes prior knowledge of 2b2t. This is an exploit for a very old Minecraft server (called 2b2t) where griefing (destroying other creations) and hacking is basically allowed. This kind of environment means that groups of players are incentivized to hide their projects out in the middle of nowhere, hundreds of thousands of blocks away from the world origin coordinates. The exploit allows a client to ask the server if data chunks at arbitrary coordinates have player activity in them, opening the server up to a brute force search to locate well-hidden bases. Basically, a group got spy satellites in an anarchy Minecraft server where remaining hidden is critical to not being destroyed.

kingcharles 5y ago
Thank you. I had no idea what was going on. This is actually pretty neat once you explain it.
Bluecobra 5y ago
This is a pretty clever exploit. I played on this server off and on between 2013-2016. The server is/was an acquired taste. The biggest challenge was to escape the the hellscape around spawn, once you get past that it was pretty quiet, I don’t ever recall running into anyone else unless I went back to the nether hub near spawn. It was really fun exploring old builds, the griefed ones were like old ruins. I liked to read the signs that were left behind and leave my own. I used to have use sone map mod and would note all the neat things I came across. I admit that I also used an x-ray mod to detect things like chests, because why not? I wonder if any of my bases were ever discovered. Most of my ill gotten gains were hidden away in a bottom of a mineshaft in the middle of nowhere to help avoid detection. Once the queue started started to get long I stopped playing.
rvnx 5y ago
In Minecraft you can dig blocks. When you click to dig a block, it just calls the RPC method CPacketPlayerDigging with the coordinates of the block. The server replies "Block of type ABC is too far". So, of course, you now know that at (X,Y,Z) you have a block of type "ABC". This RPC has no rate-limiting, so yes, you can know the whole map. The fact that you can dig any block on the map, seems like a shortcut taken by developers of the server to save time or resources. I'd even say it's almost intended behaviour. Tech details: https://2b2t.miraheze.org/wiki/Nocom https://2b2t.miraheze.org/wiki/Nocom
- leijurv 5y ago
  Not quite a shortcut, it was actually to patch a bug in vanilla minecraft that causes desync, see https://news.ycombinator.com/item?id=29621262 https://news.ycombinator.com/item?id=29621262 And it may seem silly that it tells you that it's block type ABC, but the reason is to tell your client to put it back as block ABC, instead of air. (in other words, it has to "undo" your client claiming to have mined that block [which replaces whatever it is with air]).
  - rvnx 5y ago
    I don't know why the server would give information about far-away chunks (maybe some tolerance due to possible desync why not) instead of an error code "you are too far" :/
    - leijurv 5y ago
      Well, read https://news.ycombinator.com/item?id=29621262 https://news.ycombinator.com/item?id=29621262 if you want to know why this ended up happening :)

kingcharles 5y ago

Thank you. I had no idea what was going on. This is actually pretty neat once you explain it.

Bluecobra 5y ago

This is a pretty clever exploit. I played on this server off and on between 2013-2016. The server is/was an acquired taste. The biggest challenge was to escape the the hellscape around spawn, once you get past that it was pretty quiet, I don’t ever recall running into anyone else unless I went back to the nether hub near spawn. It was really fun exploring old builds, the griefed ones were like old ruins. I liked to read the signs that were left behind and leave my own. I used to have use sone map mod and would note all the neat things I came across. I admit that I also used an x-ray mod to detect things like chests, because why not? I wonder if any of my bases were ever discovered. Most of my ill gotten gains were hidden away in a bottom of a mineshaft in the middle of nowhere to help avoid detection. Once the queue started started to get long I stopped playing.

rvnx 5y ago

In Minecraft you can dig blocks. When you click to dig a block, it just calls the RPC method CPacketPlayerDigging with the coordinates of the block. The server replies "Block of type ABC is too far". So, of course, you now know that at (X,Y,Z) you have a block of type "ABC". This RPC has no rate-limiting, so yes, you can know the whole map. The fact that you can dig any block on the map, seems like a shortcut taken by developers of the server to save time or resources. I'd even say it's almost intended behaviour. Tech details: https://2b2t.miraheze.org/wiki/Nocom https://2b2t.miraheze.org/wiki/Nocom

leijurv 5y ago
Not quite a shortcut, it was actually to patch a bug in vanilla minecraft that causes desync, see https://news.ycombinator.com/item?id=29621262 https://news.ycombinator.com/item?id=29621262 And it may seem silly that it tells you that it's block type ABC, but the reason is to tell your client to put it back as block ABC, instead of air. (in other words, it has to "undo" your client claiming to have mined that block [which replaces whatever it is with air]).
- rvnx 5y ago
  I don't know why the server would give information about far-away chunks (maybe some tolerance due to possible desync why not) instead of an error code "you are too far" :/
  - leijurv 5y ago
    Well, read https://news.ycombinator.com/item?id=29621262 https://news.ycombinator.com/item?id=29621262 if you want to know why this ended up happening :)