Node.jsApplication
CVE-2024-21896
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 · uneditedThe permission model protects itself against path traversal attacks by calling path.resolve() on any paths given by the user. If the path is to be treated as a Buffer, the implementation uses Buffer.from() to obtain a Buffer from the result of path.resolve(). By monkey-patching Buffer internals, namely, Buffer.prototype.utf8Write, the application can modify the result of path.resolve(), which leads to a path traversal vulnerability. This vulnerability affects all users using the experimental permission model in Node.js 20 and Node.js 21. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.
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 confidenceA path traversal vulnerability exists in Node.js experimental permission model where monkey-patching Buffer.prototype.utf8Write allows attackers to modify the result of path.resolve(), bypassing security protections. The flaw occurs because Buffer.from() is used on path.resolve() results, making the path vulnerable to manipulation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Node.jsApplication
>= 20.0.0, < 20.11.1>= 21.0.0, < 21.6.2CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 installed Node.js versionRun 'node --version' or 'node -p "process.version"' to get the exact version stringAffected if Version is >= 20.0.0 and < 20.11.1, or >= 21.0.0 and < 21.6.2
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Verify if experimental permission model is enabledCheck startup scripts, package.json scripts, or process launch arguments for the --experimental-permission flag. Run 'node --help | grep permission' to confirm flag availability, then inspect your application's launch configurationAffected if The --experimental-permission flag is present in the Node.js process arguments or configuration
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Inspect for Buffer.prototype.utf8Write monkey-patchingSearch codebase for patterns like 'Buffer.prototype.utf8Write =' or 'Object.getOwnPropertyDescriptor(Buffer.prototype, "utf8Write")' using grep or code search toolsAffected if Code modifies or reassigns Buffer.prototype.utf8Write in your application or loaded modules
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Check for code using path.resolve with external inputReview code that uses path.resolve() where output feeds into file system operations, particularly in applications using the experimental permission modelAffected if path.resolve results are used for file operations and the experimental permission model is active
You are affected if running a Node.js version in the vulnerable range AND the experimental permission model (--experimental-permission) is enabled in your runtime environment.
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 · scoped20.11.121.6.2
Disable the experimental permission model in Node.js 20/21 until a patched version is available, or upgrade to a fixed release when published. Avoid using this experimental feature in production environments.
Node.js 20.11.1+ or 21.6.2+ (preferably Node.js 20.x LTS)
- Check current Node.js version with: node --version
- If running Node.js 20.x and version is less than 20.11.1, upgrade to version 20.11.1 or later
- If running Node.js 21.x and version is less than 21.6.2, upgrade to version 21.6.2 or later
- Consider upgrading to the latest stable LTS version (currently Node.js 20.x LTS) for long-term support and additional security fixes
- After upgrade, verify the new version: node --version
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Node.js
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-21896 — 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-2024-21896 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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