CVE-2024-56141 Overview
CVE-2024-56141 affects Minosoft, an open-source multi-version Minecraft Java Edition client written in Kotlin. The CryptManager.kt encryption routine initializes its Advanced Encryption Standard (AES) cipher using an initialization vector (IV) set equal to the secret key rather than a random value. This cryptographic flaw exposes the encryption to chosen-plaintext and chosen-ciphertext attacks. An attacker who can submit specific messages for encryption can recover the secret key. The issue affects all versions supporting Minecraft protocol 1.7 and later, starting from commit f1ae30e2b046a490026a8413b075685deb795122.
Critical Impact
An attacker capable of influencing encrypted messages between a Minosoft client and a Minecraft server can recover the AES secret key, compromising the confidentiality and integrity of the encrypted session.
Affected Products
- Minosoft (Minecraft Java Edition client)
- All versions supporting Minecraft protocol 1.7 and later
- Builds derived from commit f1ae30e2b046a490026a8413b075685deb795122
Discovery Timeline
- 2026-07-07 - CVE-2024-56141 published to the National Vulnerability Database (NVD)
- 2026-07-08 - Last updated in NVD database
Technical Details for CVE-2024-56141
Vulnerability Analysis
The vulnerability is a cryptographic weakness classified as [CWE-329]: Generation of Predictable IV with Cipher in Cipher Block Chaining (CBC) Mode. Minosoft's CryptManager.kt initializes the AES cipher used for Minecraft network encryption with an IV derived directly from the shared secret key. Modern AES modes such as CBC and Counter (CTR) require an IV that is unpredictable and independent of the key. Reusing the key material as the IV breaks the security guarantees of the underlying block cipher mode.
Because the IV equals the key, the ciphertext leaks structural information that would normally be hidden. An attacker who can request encryption of chosen plaintexts, or who can observe ciphertexts and manipulate them, can mount adaptive attacks that recover key bits. Once the key is recovered, the attacker can decrypt the full session and forge additional traffic.
Root Cause
The root cause is an insecure implementation choice in the CryptManager encryption routine within CryptManager.kt. The developer passed the AES secret key as the IV parameter when initializing the cipher instead of generating a random IV. This eliminates the entropy required for IV uniqueness and unpredictability, invalidating the cryptographic assumptions of the cipher mode.
Attack Vector
Exploitation occurs over the network. An adversary must be positioned to influence the plaintext content encrypted by the Minosoft client, such as through a malicious Minecraft server or a man-in-the-middle position on the network path. The attacker submits crafted messages, observes the resulting ciphertext, and uses the relationship between the IV and key to derive the secret key. The attack requires low privileges but high attack complexity because it depends on the ability to inject or observe multiple chosen plaintexts.
No patched version is available at the time of publication, and no verified proof-of-concept code has been released. See the GitHub Security Advisory GHSA-rvr6-48rj-c94j and the vulnerable code in CryptManager.kt for technical details.
Detection Methods for CVE-2024-56141
Indicators of Compromise
- Presence of Minosoft builds compiled from or after commit f1ae30e2b046a490026a8413b075685deb795122.
- Outbound Minecraft protocol 1.7+ connections originating from Minosoft clients to untrusted or unknown servers.
- Unexpected reconnections or session anomalies suggesting protocol tampering during encrypted Minecraft sessions.
Detection Strategies
- Perform static analysis of CryptManager.kt in local Minosoft builds to confirm whether the IV parameter passed to Cipher.init() matches the secret key material.
- Inventory endpoints for Minosoft installations and correlate installed commits against the vulnerable range published in the advisory.
- Inspect Minecraft session captures for encryption negotiation patterns that align with the vulnerable protocol handshake.
Monitoring Recommendations
- Log and alert on network traffic to Minecraft servers from developer or gaming endpoints in enterprise environments.
- Monitor code repositories and package registries for redistribution of vulnerable Minosoft builds.
- Track upstream project releases and the associated GitHub advisory for a fixed commit or version tag.
How to Mitigate CVE-2024-56141
Immediate Actions Required
- Restrict or block use of Minosoft clients until an upstream fix is available, particularly on managed endpoints.
- Avoid connecting Minosoft clients to untrusted Minecraft servers where an attacker could submit chosen plaintexts.
- Rotate any credentials or session material that may have been transmitted through a vulnerable Minosoft session.
Patch Information
No patched version is available at the time of publication. Users and administrators should monitor the Minosoft GitHub Security Advisory GHSA-rvr6-48rj-c94j for updates. When a fix is released, it should replace the key-derived IV with a cryptographically secure random IV generated per session using SecureRandom, and the IV should be transmitted alongside the ciphertext as required by the selected AES mode.
Workarounds
- No official workarounds are available from the maintainer.
- Discontinue use of Minosoft for encrypted Minecraft sessions until an upstream fix lands.
- If source builds are used, apply a private patch that generates a random IV independent of the AES key before deploying the client.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
