BookExploitFix 0.15

Fixes an exploit allowing hack clients to create books with JSON commands

  1. minoneer
    Native Minecraft Version:
    Tested Minecraft Versions:
    • 1.8
    • 1.9
    • 1.10
    • 1.11
    • 1.12
    • 1.13
    • 1.14
    • 1.15
    This plugin aims to fix an exploit on recent Spigot/CraftBukkit servers which allows players to create books which execute commands on click.

    Does my server need this plugin?

    Your server is vulnerable to this exploit when ONE of these conditions are met:
    Your server version is between 1.8 and 1.8.3
    Your server version is 1.8 or newer (including 1.9, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15) and players have creative mode

    How does it work?
    Since version 1.8, book pages are stored as JSON strings, which allow to encode actions when the text is clicked. This includes opening URL, executing commands, etc. Hackers exploit this by encoding commands like /op and then try to get someone with the appropriate permissions to click the page. In less drastic cases, they can use it to get unsuspecting players to transfer money, give build permissions, etc.

    What does the plugin do?

    This plugin counters these atempts by filtering the book pages on certain ingame events and replacing the potentially harmful actions with a simple and harmless hover message.

    Plugin Description


    /filter - Actively applies the filter on the book in your hand.
    aliases: /bookfilter | /filterbook


    bookfilter.filter - Gives access to the /filter command
    bookfilter.overridefilter - Overrides filtering when reading books


    CraftBukkit or Spigot version 1.8 - 1.15
    Java 8 or newer

    I recommend to "Watch This Resource" as I will push critical fixes as fast as I can. Any feedback and suggestions for improvement are very welcome!

    Spigot has fixed the exploit for survival mode in this commit which means in spitogt/craftbukkit version 1.8.3 and later. In creative mode, inventories are handled differently and is therefore still affected.

    Disclaimer: I have testet this plugin in test and live environments. However, plugins can always contain bugs and unintended behaviour. If you use this plugin, you do so on your own risk. I cannot be held responsible for any consequences from using this plugin. If you encounter any bugs, please report them so they can be fixed.

Recent Reviews

  1. Nickster258
    Version: 0.15
    While this plugin works, updates are slow and servers are left vulnerable to these exploits while waiting. This is frustrating as updating the plugin is trivial. Sadly, it imports the net.minecraft server classes of the specified version instead of using Java reflection to dynamically load the necessary classes. The core of the fix has not changed since 1.8.
  2. __Vekster007__
    Version: 0.15
    Good! Good! Good! Good! Good! Good! Good! Good! Good! Good! Good! Good! Good! Good!
  3. coolpvpv
    Version: 0.15
    ill give it a 2 sense it doesn't make the server crash with jigaws servercrasher mode set to the tothedumpster but it still lags the crap out of it where it cant be playable
    1. minoneer
      Author's Response
      Preventing server crashes due to malicious packages is not the purpose of this plugin. Please do not review plugins on tasks they were never meant to do.
  4. hjk321
    Version: 0.14
    Absolutely brilliant. Supposedly the exploit is patched for some versions but why risk it? The included command allows it to be easily tested too which is a nice plus.
  5. TaquitoNortenio
    Version: 0.14
    ¬°Un muy gran complemento, gracias por ayudar a mejorar la comunidad en contra de los hackers! [ESP]
  6. Nirewen
    Version: 0.13
    Excelent plugin! It worked like a charm. I was wondering if you could do the same for signs with commands too. I have a creative server and users started to create custom signs and for some reason the commands executed in them have op permission. It would be great to have this disabled and I didn't find anything about this on the internet
  7. X00LA
    Version: 0.11
    Great Plugin for all who wants to keep their servers clean and secure.


    Please keep up this nice peace of code!
  8. skino0
    Version: 0.11
    Sounds good! Im gonna check this out <3 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  9. frizzbee30
    Version: 0.9
    Great extra layer of protection for those of us who run the latest spigot, and have creative worlds or allow GM1 in survival etc :)
  10. dvargas135
    Version: 0.7
    You don't need this for 1.9 and above... Why update? Lol. It's only for 1.8.3 and below
    1. minoneer