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:

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:

config/CSC/user_rule.json

Online cached rules:

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:

• crackun24 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.