CVE-2021-4307Public exploitNetwork attack vector

Object prototype modification via unsafe recursive merge

Published Jan 7, 2023 · Updated Nov 25, 2024

Prototype pollution in Yomguithereal Baobab 2.0 through 2.6.0 allows attackers to modify Object.prototype via crafted merge data. The deepMerge helper recursively traverses enumerable keys and, before the fix, treats proto, constructor, and prototype as ordinary merge keys. Exploitation requires a consuming application to pass attacker-controlled objects to deepMerge; polluted properties then affect other objects in that JavaScript process.

CVSS severity9.8
Critical
EPSS probability1.27%
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 Yomguithereal Baobab 2.0 through 2.6.0 allows attackers to modify Object.prototype via crafted merge data. The deepMerge helper recursively traverses enumerable keys and, before the fix, treats proto, constructor, and prototype as ordinary merge keys. Exploitation requires a consuming application to pass attacker-controlled objects to deepMerge; polluted properties then affect other objects in that JavaScript process.

The record

CVE
CVE-2021-4307
Published
Jan 7, 2023
Updated
Nov 25, 2024
Vendor
Yomguithereal
Product
Baobab
Classifications
CWE-1321, CAPEC-180, CAPEC-77, CAPEC-1
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jan 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 25, 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
  2. Affected versionversion=2.1
  3. Affected versionversion=2.2
  4. Affected versionversion=2.3
  5. Affected versionversion=2.4
  6. Affected versionversion=2.5
  7. Affected versionversion=2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Yomguithereal · Baobabversion=2.0; version=2.1; version=2.2; version=2.3; version=2.4; version=2.5; version=2.6

Published CVSS scores

6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CAPEC-180Exploiting Incorrectly Configured Access Control Security Levels
CAPEC-77Manipulating User-Controlled Variables
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs

Public exploit references

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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