CVE-2024-41564 – This vulnerability in EMI mod for Minecraft all... (How to Fix)

Q: What is the severity of CVE-2024-41564?

CVE-2024-41564 has a CVSS score of 4.3 (MEDIUM). This vulnerability in EMI mod for Minecraft allows in-game item duplication through improper validation of slot indexes and stack counts. It affects all Minecraft servers running EMI mod version 1.1.10 or earlier. The issue enables players to duplicate items within the game economy.

📋 TL;DR

This vulnerability in EMI mod for Minecraft allows in-game item duplication through improper validation of slot indexes and stack counts. It affects all Minecraft servers running EMI mod version 1.1.10 or earlier. The issue enables players to duplicate items within the game economy.

💻 Affected Systems

Products:

EMI (Easy Minecraft Inventory) mod for Minecraft

Versions: v1.1.10 and earlier

Operating Systems: All operating systems running Minecraft with EMI mod

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects Minecraft servers with EMI mod installed. Single-player worlds are also vulnerable but impact is limited to local game.

📦 What is this software?

Emi by Emilyploszaj

View all CVEs affecting Emi →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete disruption of in-game economy through mass item duplication, leading to server instability and player dissatisfaction.

🟠

Likely Case

Moderate economic disruption as players exploit the bug to duplicate valuable items, requiring server rollbacks or manual intervention.

🟢

If Mitigated

Minimal impact if detected early and players are prevented from exploiting before patching.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: CONFIRMED

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploit requires authenticated player access. Public proof-of-concept exists in GitHub gist.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: v1.1.11

Vendor Advisory: https://github.com/emilyploszaj/emi/blob/1.21/xplat/src/main/java/dev/emi/emi/network/FillRecipeC2SPacket.java

Restart Required: Yes

Instructions:

1. Download EMI v1.1.11 from official sources. 2. Replace existing EMI mod files with new version. 3. Restart Minecraft server. 4. Verify version shows 1.1.11.

🔧 Temporary Workarounds

Disable EMI mod temporarily

all

Remove or disable EMI mod until patched

mv emi-*.jar emi-disabled.jar
# Move EMI jar file to disable

Restrict player permissions

all

Limit player access to crafting/recipe functions

🧯 If You Can't Patch

Monitor server logs for unusual item duplication patterns
Implement regular server backups to restore state if exploitation occurs

🔍 How to Verify

Check if Vulnerable:

Check EMI mod version in server mods folder. If version is 1.1.10 or earlier, system is vulnerable.

Check Version:

ls -la mods/emi-*.jar | grep -o 'emi-[0-9.]*\.jar'

Verify Fix Applied:

Verify EMI mod version shows 1.1.11 and test that item duplication no longer works.

📡 Detection & Monitoring

Log Indicators:

Unusual item count changes
Rapid inventory modifications
Multiple identical item transactions in short time

Network Indicators:

Abnormal packet frequency to FillRecipeC2SPacket handler

SIEM Query:

source="minecraft.log" AND "FillRecipeC2SPacket" AND count(item_id) > threshold

📊 Metadata

CVE ID: CVE-2024-41564

CVSS v3 Score: 4.3 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CWE: CWE-129

Published: August 28, 2024

Last Updated: March 26, 2025

🔗 References

https://gist.github.com/apple502j/6d691b62c37fc37b03b0784917064df6 Third Party Advisory
https://github.com/emilyploszaj/emi/blob/1.21/xplat/src/main/java/dev/emi/emi/network/FillRecipeC2SPacket.java Issue Tracking

📤 Share & Export

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🔗 Related Vulnerabilities

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