Node.jsApplication
CVE-2023-39332
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 · uneditedVarious `node:fs` functions allow specifying paths as either strings or `Uint8Array` objects. In Node.js environments, the `Buffer` class extends the `Uint8Array` class. Node.js prevents path traversal through strings (see CVE-2023-30584) and `Buffer` objects (see CVE-2023-32004), but not through non-`Buffer` `Uint8Array` objects. This is distinct from CVE-2023-32004 which only referred to `Buffer` objects. However, the vulnerability follows the same pattern using `Uint8Array` instead of `Buffer`. 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 confidenceNode.js `node:fs` functions accept paths as strings, `Buffer`, or `Uint8Array` objects. While path traversal protections exist for strings (CVE-2023-30584) and `Buffer` objects (CVE-2023-32004), non-Buffer `Uint8Array` objects bypass these protections, allowing attackers to access files outside intended directories.
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, < 20.8.0
FedoraOperating system
= 39CVSS 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 version stringAffected if Version is >= 20.0.0 and < 20.8.0
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Identify Node.js major versionParse the major version number from the version string (e.g., v20.x.x = 20)Affected if Major version is 20 and minor/patch is below 8.0.0
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Audit code for Uint8Array path usageSearch codebase for fs function calls (e.g., fs.readFile, fs.writeFile, fs.access) where Uint8Array is passed as the path argumentAffected if Code passes Uint8Array objects to fs functions without validation
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Check for experimental permission modelInspect Node.js startup flags or environment (e.g., `node --experimental-permission ...`)Affected if Experimental permission model is NOT enabled and Node.js version is in the affected range
Environment is affected if running Node.js version 20.0.0 through 20.7.x and code uses fs functions with Uint8Array path inputs without the experimental permission model enabled.
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 · scoped20.8.0
Upgrade Node.js to a patched version that addresses this vulnerability, and/or enable the experimental permission model to restrict filesystem access.
Node.js 20.8.0
- Check current Node.js version by running `node --version`
- Upgrade Node.js to version 20.8.0 or later
- Verify the upgrade was successful by running `node --version` again
- If using a package manager (npm, nvm, or system package manager), ensure the package manager is updated to reflect the new version
- Test that applications using `node:fs` functions with Uint8Array paths work correctly after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Node.js
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 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 $3,392.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-39332 — 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-2023-39332 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
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