Create: SchematicChecker

Create: Schematic Checker (CSC)

Create: Schematic Checker is a server-side protection mod for Create schematics. It scans uploaded schematics and blocks or sanitizes known malicious NBT patterns before they can be printed into a world.

CSC is designed for public and survival servers that allow schematic uploads. It protects against known Create schematic exploits such as item duplication, creative-item acquisition, server lag, crashes, malformed contraptions, and dangerous addon NBT.

Support

- Discord: https://discord.gg/rQV5JPauY7

What It Does

- Scans schematics asynchronously, without blocking the Minecraft server main thread. - Detects and blocks known malicious Create schematic exploits. - Sanitizes configurable NBT fields, tags, blocks, items, and entities. - Validates Create belts, chain drives, mechanical arms, filters, fluid tanks, clipboards, and other high-risk block entities. - Supports custom local rules through `config/CSC/user_rule.json`. - Can optionally sync online rule updates when enabled by the server owner. - Keeps logs and optional schematic backups for auditing and later investigation.

Supported Versions

Choose the build that matches both your Minecraft version and Create version.

| Loader | Minecraft | Create target | | --- | --- | --- | | Forge | 1.14.4 | 0.2.3 | | Forge | 1.15.2 | 0.3.1 | | Forge | 1.16.5 | 0.3.2g | | Forge | 1.17.1 | 0.4 | | Forge | 1.18.2 | 0.5.1i | | Forge | 1.19.2 | 0.5.1i | | Forge | 1.20.1 | 0.5.1j | | Forge | 1.20.1 | 6.0.x | | Fabric | 1.18.2 | 0.5.1i | | Fabric | 1.19.2 | 0.5.1i | | Fabric | 1.20.1 | 6.0.x | | Fabric | 1.21.1 | 6.0.x | | NeoForge | 1.21.1 | 6.0.x |

Dependencies

- Minecraft - Create

Some builds may require loader-specific Create dependencies such as Flywheel, Ponder, or Registrate, depending on the target Minecraft/Create version.

Installation

1. Download the CSC jar for your loader, Minecraft version, and Create version. 2. Put the jar into the server `mods` folder. 3. Start the server once to generate `config/CSC/config.toml`. 4. Review the generated configuration before opening schematic uploads to players. 5. Use `/csc reload` after editing the config.

Configuration

Main config file:

```text config/CSC/config.toml ```

Important options:

| Option | Purpose | | --- | --- | | `core.Enable` | Enables or disables CSC checks. | | `core.BanBlock` | Blocks or sanitizes high-risk blocks and items. | | `core.BanTag` | Removes or blocks dangerous NBT tags. | | `core.KillEntity` | Removes entities from schematics to prevent entity-based exploits. | | `core.WhiteListModEnable` | Allows only listed mod IDs to keep NBT. Recommended for public servers. | | `debug.EnableBackup` | Saves uploaded schematics for later auditing. Recommended. | | `online.enableAutoUpdate` | Allows CSC to fetch cloud rule updates. Disabled by default. | | `online.enableManualConfig` | Enables custom rules from `config/CSC/user_rule.json`. |

Manual custom rule file:

```text config/CSC/user_rule.json ```

Online cached rules:

```text config/CSC/online/ ```

Commands

| Command | Description | | --- | --- | | `/csc` | Shows basic status. | | `/csc help` | Shows help and feedback links. | | `/csc reload` | Reloads CSC configuration and rules. | | `/csc list` | Shows rule-list help. | | `/csc list IdMatchRuleAll` | Lists all ID match rules. | | `/csc list OperateMatchRuleAll` | Lists all NBT operation rules. | | `/csc DisableTemp` | Temporarily disables checks for 5 minutes. | | `/csc Enable` | Restores CSC after temporary disable. | | `/csc notice whitelistid on|off` | Toggles whitelist-mode scan notice. | | `/csc mode whitelistid on|off` | Toggles mod ID whitelist mode. |

Known Exploit Coverage

CSC covers many reported Create schematic vulnerabilities and addon-specific NBT exploits.

| # | Status | Issue | | --- | --- | --- | | 1 | Fixed | Creative items printed through Lecterns or Clipboards. | | 2 | Fixed | Valve data tampering causing cache overflow and memory leaks. | | 3 | Fixed | Clipboard duplication and creative-property clipboards. | | 4 | Fixed | Conveyor belt length tampering beyond 1000 blocks. | | 5 | Fixed | Conveyor belts with `-1` length crashing older Forge servers. | | 6 | Fixed | Massive malicious conveyor chains causing lag, crashes, or world damage. | | 7 | Fixed | Kintsugi Decor Urn infinite game-tick exploit. | | 8 | Fixed | Weighted Ejector launch-force tampering. | | 9 | Fixed | Oversized Filter NBT causing extreme tick lag. | | 10 | Fixed | Overlong chain-drive pairings causing server lag. | | 11 | Fixed | `using_converts_to` tag creative-item exploit. | | 12 | Fixed | Mechanical Arm distance tampering. | | 13 | Fixed | Chain drives targeting invalid positions. | | 14 | Fixed | Distorted conveyor belts causing belt or shaft duplication. | | 15 | Fixed | Chain drives with thousands of targets causing lag and duplication. | | 16 | Fixed | Mechanical Arm infinite output through tampered safe-NBT data. | | 17 | Fixed | Mechanical Arm duplication with camouflage panel mods. | | 18 | Fixed | Filter retrieval through Andesite Hoppers. | | 19 | Fixed | Creative-item acquisition through burn tags. | | 20 | Fixed | Entity-based duplication and creative-item exploits, including Armor Stands. | | 21 | Fixed | Roller-related creative item exploit in specific versions. | | 22 | Fixed | Create: Enchantment Industry creative-tag printing. | | 23 | Fixed | Create Crafts & Additions infinite energy-cell printing. | | 24 | Fixed | Integrated Farming Chicken Coop GT lag exploit. | | 25 | Fixed | Command-execution NBT exploit. | | 26 | Fixed | Create 6.0+ fluid tank capacity tampering. | | 27 | Fixed | Quark Wire Mesh infinite lava exploit. | | 28 | Fixed | Item teleportation to the void through modified mechanical crafters/synthesizers. | | 29 | Fixed | Additional void item-teleport exploit variants. | | 30 | Fixed | Super Glue adhesion-check abuse causing heavy lag or crashes. | | 31 | Fixed | Chassis and angled-chassis adhesion-check abuse causing heavy lag or crashes. | | 32 | Detected | Create: Big Cannons fuse-data tampering for creative-item acquisition. | | 33 | Fixed | Twilight Forest giant block printing bypassing terrain and breaking bedrock. |

Acknowledgments

Special thanks to:

- 一只不屑的屑蜘蛛 for Mixin reference code. - Qifei de Meigui, Kong Yu, air, crackun24, runner, CTR server owner, and other Create public server owners for test samples and post-fix support. - Some CMS blueprint-site partner creators. Their decision to block the author after seeing schematic bug fixes also became part of the motivation to keep this project updated. - Bilibili creator 一只不屑的屑蜘蛛. The repeated public-server schematic attacks and spread of exploit samples directly motivated this project and helped accelerate fixes for Create schematic vulnerabilities.

License

This project is licensed under GNU LGPL 3.0.