CVE-2021-21304Network attack vector

Prototype pollution via unsafe final-key assignment

Published Feb 8, 2021 · Updated Aug 3, 2024

Prototype pollution in Dynamoose 2.0.0 through 2.6.0 allows remote attackers to inject special object properties via crafted keys. The lib/utils/object/set.ts utility assigned values to final proto or constructor keys without rejecting those special property names. Exposure requires consuming code to pass attacker-controlled keys into the utility, resulting in inherited-property injection that alters downstream application behavior.

CVSS severity7.2
High
EPSS probability1.89%
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 Dynamoose 2.0.0 through 2.6.0 allows remote attackers to inject special object properties via crafted keys. The lib/utils/object/set.ts utility assigned values to final proto or constructor keys without rejecting those special property names. Exposure requires consuming code to pass attacker-controlled keys into the utility, resulting in inherited-property injection that alters downstream application behavior.

The record

CVE
CVE-2021-21304
Published
Feb 8, 2021
Updated
Aug 3, 2024
Vendor
Dynamoose
Product
Dynamoose
Classifications
CWE-1321, CWE-915
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=>= 2.0.0, < 2.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Dynamoose · Dynamooseversion=>= 2.0.0, < 2.7.0

Published CVSS scores

7.2GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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