CVE-2024-39840
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFactorio before 1.1.101 allows a crafted server to execute arbitrary code on clients via a custom map that leverages the ability of certain Lua base module functions to execute bytecode and generate fake objects.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceFactorio before version 1.1.101 contains a vulnerability where a malicious server can send crafted custom maps to clients. The map exploits Lua base module functions that can execute bytecode and generate fake objects, allowing arbitrary code execution on connected clients.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Factorio versionLaunch the Factorio game client and look at the version number displayed on the main menu or in the game properties. Alternatively, check the version in the Steam library or the Factorio launcher.Affected if The installed version is earlier than 1.1.101 (for example, 1.1.100, 1.1.99, etc.)
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Identify server connection usageReview recent game activity to determine if you have connected to any multiplayer servers, particularly custom or untrusted servers that send custom maps to clients.Affected if You have connected to multiplayer servers that transmit custom map data to your client.
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Assess trust level of connected serversReview the list of servers you have connected to and evaluate whether they are known, trusted servers or potentially untrusted sources sending custom map data.Affected if You have connected to servers that you do not fully trust or that send unsolicited custom map content.
You are affected if your Factorio version is earlier than 1.1.101 AND you have connected to multiplayer servers that send custom maps to your client, as the vulnerability allows arbitrary code execution through crafted map data.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpdate Factorio to version 1.1.101 or later. Clients should avoid connecting to untrusted servers until the update is applied.
Factorio 1.1.101 or later
- Ensure Factorio is not currently running
- Open the Factorio launcher or game client
- Check for updates through the game's built-in update mechanism, or download version 1.1.101 or later from the official Factorio website (factorio.com)
- Launch the updated game client to verify the version displayed matches 1.1.101 or higher
- If running a dedicated server, update the server installation to version 1.1.101 or later using the headless server package
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-39840 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-39840 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data