CVE-2020-8147Public exploitNetwork attack vector

Code execution or crashes via unrestricted prototype writes

Published Apr 3, 2020 · Updated Aug 4, 2024

Prototype pollution in douzi8 utils-extend 1.0.8 and earlier allows remote attackers to execute code or crash applications. The extend function copies attacker-controlled property names without blocking proto, allowing writes to Object.prototype. Exploitation requires a consuming application to pass attacker-controlled objects to extend; polluted properties then affect objects in that Node.js process.

CVSS severity9.8
Critical
EPSS probability3.15%
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 douzi8 utils-extend 1.0.8 and earlier allows remote attackers to execute code or crash applications. The extend function copies attacker-controlled property names without blocking proto, allowing writes to Object.prototype. Exploitation requires a consuming application to pass attacker-controlled objects to extend; polluted properties then affect objects in that Node.js process.

The record

CVE
CVE-2020-8147
Published
Apr 3, 2020
Updated
Aug 4, 2024
Vendor
douzi8
Product
utils-extend
Classifications
CWE-471, CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=Not Fixed
  2. Affected versionversion=version 1.0.8 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

douzi8 · utils-extendversion=Not Fixed; version=version 1.0.8 and earlier

Published CVSS scores

7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST National Vulnerability DatabaseCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-471Modification of Assumed-Immutable Data (MAID)
CWE-20Improper Input Validation
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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