CVE-2021-23574Public exploitNetwork attack vector

Prototype pollution via unchecked keys and paths

Published Dec 24, 2021 · Updated Sep 16, 2024

Prototype pollution in JSData 3.0.10 and earlier allows attackers to modify Object.prototype through crafted keys or paths. The deepFillIn merge recursively follows an attacker-controlled proto key into Object.prototype, while set passes crafted path segments through mkdirP without rejecting prototype names. Reachability requires a consuming application to pass untrusted objects or property paths to either utility; the demonstrated consequence is process-wide inherited-property modification, while further effects depend on how the application uses polluted properties.

CVSS severity7.5
High
EPSS probability2.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in JSData 3.0.10 and earlier allows attackers to modify Object.prototype through crafted keys or paths. The deepFillIn merge recursively follows an attacker-controlled proto key into Object.prototype, while set passes crafted path segments through mkdirP without rejecting prototype names. Reachability requires a consuming application to pass untrusted objects or property paths to either utility; the demonstrated consequence is process-wide inherited-property modification, while further effects depend on how the application uses polluted properties.

The record

CVE
CVE-2021-23574
Published
Dec 24, 2021
Updated
Sep 16, 2024
Vendor
js-data
Product
JSData
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 24, 2021CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

js-data · JSDataversion=0 <unspecified

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
7.5SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Public exploit references

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Technologies

Your stack

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Your stack

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