CVE-2021-4229Known exploitationNetwork attack vector

Credential theft and cryptomining via malicious install script

Published May 24, 2022 · Updated Apr 15, 2025

Embedded malware in UAParser.js 0.7.29, 0.8.0, and 1.0.0 allows attackers to steal credentials and perform cryptocurrency mining during installation. The package's preinstall.js script selects a Linux shell script or Windows batch file, downloads an XMRig payload, and on Windows loads a password-stealing DLL. Execution requires installation of a compromised release; Linux hosts run the cryptominer outside four excluded countries, while Windows hosts also expose stored application and Credential Manager passwords.

CVSS severity8.8
High
EPSS probability1.42%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Embedded malware in UAParser.js 0.7.29, 0.8.0, and 1.0.0 allows attackers to steal credentials and perform cryptocurrency mining during installation. The package's preinstall.js script selects a Linux shell script or Windows batch file, downloads an XMRig payload, and on Windows loads a password-stealing DLL. Execution requires installation of a compromised release; Linux hosts run the cryptominer outside four excluded countries, while Windows hosts also expose stored application and Credential Manager passwords.

The record

CVE
CVE-2021-4229
Published
May 24, 2022
Updated
Apr 15, 2025
Vendor
Faisal Salman
Product
UAParser.js
Classifications
CWE-506, CWE-912, T1496, T1059.001, T1218.010, T1555
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 22, 2021Exploitation reportedMalicious ua-parser-js releases distributed through npm
  2. May 24, 2022CVE publishedPublication date reported by the CVE source.
  3. Apr 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.7.29
  2. Affected versionversion=0.8.0
  3. Affected versionversion=1.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Faisal Salman · UAParser.jsversion=0.7.29; version=0.8.0; version=1.0.0

Published CVSS scores

8.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-506Embedded Malicious Code
CWE-912Hidden Functionality
T1496Resource Hijacking
T1059.001PowerShell
T1218.010Regsvr32
T1555Credentials from Password Stores

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.

Reported exploitation

Technologies

Your stack

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Your stack

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