Prototype pollution via unfiltered recursive merge keys
Published Jan 31, 2021 · Updated Sep 16, 2024
Prototype pollution in nested-object-assign before 1.0.4 allows attackers to modify Object.prototype through crafted merge input. The default nestedObjectAssign function recursively traverses source keys without excluding proto, constructor, or prototype, so writes descend into the shared prototype. Exploitation requires a consuming application to pass attacker-controlled objects to the merge API; polluted inherited properties corrupt application state or crash code that expects other property types.
Summary
What happened
Prototype pollution in nested-object-assign before 1.0.4 allows attackers to modify Object.prototype through crafted merge input. The default nestedObjectAssign function recursively traverses source keys without excluding proto, constructor, or prototype, so writes descend into the shared prototype. Exploitation requires a consuming application to pass attacker-controlled objects to the merge API; polluted inherited properties corrupt application state or crash code that expects other property types.
The record
- CVE
- CVE-2021-23329
- Published
- Jan 31, 2021
- Updated
- Sep 16, 2024
- Vendor
- Geta Digital
- Product
- nested-object-assign
- Classifications
- CWE-1321, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 31, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 2024Record 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=unspecified <1.0.4
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
- Upstream prototype-pollution proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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