File access bypass via monkey-patched Buffer internals
Published Feb 20, 2024 · Updated Apr 30, 2025
Path traversal in Node.js 20.0.0 through 20.11.0 and 21.0.0 through 21.6.1 allows local users to bypass file permissions. Buffer.from converts a path.resolve result through the mutable Buffer.prototype.utf8Write method, allowing executed JavaScript to replace the normalized path after validation. Exploitation requires the experimental permission model and attacker-controlled JavaScript execution, enabling reads or writes outside configured filesystem paths.
Summary
What happened
Path traversal in Node.js 20.0.0 through 20.11.0 and 21.0.0 through 21.6.1 allows local users to bypass file permissions. Buffer.from converts a path.resolve result through the mutable Buffer.prototype.utf8Write method, allowing executed JavaScript to replace the normalized path after validation. Exploitation requires the experimental permission model and attacker-controlled JavaScript execution, enabling reads or writes outside configured filesystem paths.
The record
- CVE
- CVE-2024-21896
- Published
- Feb 20, 2024
- Updated
- Apr 30, 2025
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- CWE-27
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 20, 2024CVE publishedPublication date reported by the CVE source.
- Apr 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0 <10.*
- Affected versionversion=11.0 <11.*
- Affected versionversion=12.0 <12.*
- Affected versionversion=13.0 <13.*
- Affected versionversion=14.0 <14.*
- Affected versionversion=15.0 <15.*
- Affected versionversion=16.0 <16.*
- Affected versionversion=17.0 <17.*
- Affected versionversion=19.0 <19.*
- Affected versionversion=20.0 <20.11.1
- Affected versionversion=21.0 <21.6.2
- Affected versionversion=4.0 <4.*
- Affected versionversion=5.0 <5.*
- Affected versionversion=6.0 <6.*
- Affected versionversion=7.0 <7.*
- Affected versionversion=8.0 <8.*
- Affected versionversion=9.0 <9.*
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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