Prototype pollution via unchecked recursive merge keys
Published Feb 18, 2021 · Updated Sep 16, 2024
Prototype pollution in the merge npm package before 2.1.1 allows remote attackers to modify Object.prototype via crafted merge input. The _recursiveMerge function assigns attacker-controlled keys to the destination without excluding proto, constructor, or prototype. Exploitation requires an application to pass attacker-controlled objects into recursive merging; polluted inherited properties can alter that application's behavior.
Summary
What happened
Prototype pollution in the merge npm package before 2.1.1 allows remote attackers to modify Object.prototype via crafted merge input. The _recursiveMerge function assigns attacker-controlled keys to the destination without excluding proto, constructor, or prototype. Exploitation requires an application to pass attacker-controlled objects into recursive merging; polluted inherited properties can alter that application's behavior.
The record
- CVE
- CVE-2020-28499
- Published
- Feb 18, 2021
- Updated
- Sep 16, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-915
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 18, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Snyk recursive-merge proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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