CVE-2021-4229 | ua-parser-js Crypto Mining backdoor

A vulnerability was found in ua-parser-js 0.7.29/0.8.0/1.0.0. It has been rated as critical. This issue affects the crypto mining component which introduces a backdoor. Upgrading to version 0.7.30, 0.8.1 and 1.0.1 is able to address this issue. It is recommended to upgrade the affected component.

Published: 2022-05-24 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-4229 is rated Moderate Risk (46.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.86%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-4229

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-17 0.82% 0.86% +0.04%
2 2025-06-29 0.57% 0.82% +0.25%
3 2025-05-25 — 0.57% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-4229

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.6 3.4 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
7.6 2.0 HIGH
AV:N/AC:H/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 4.9 10.0 [email protected]

Weakness enumeration for CVE-2021-4229

GitHub Security Advisory for CVE-2021-4229

OS Trackers for CVE-2021-4229

vendor priority summary link
debian unimportant CVE-2021-4229 unimportant priority: Debian including 1 source packages (node-ua-parser-js), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-4229
ubuntu medium CVE-2021-4229 medium priority: Ubuntu including 1 source packages (node-ua-parser-js), 5 status rows across 5 suites (bionic, focal, impish, jammy, upstream): not-affected 4, released 1. https://ubuntu.com/security/CVE-2021-4229

Affected software / configurations for CVE-2021-4229

Vendor Product Version Raw CPE
ua-parser-js_project ua-parser-js 0.7.29 cpe:2.3:a:ua-parser-js_project:ua-parser-js:0.7.29:*:*:*:*:node.js:*:*
ua-parser-js_project ua-parser-js 0.8.0 cpe:2.3:a:ua-parser-js_project:ua-parser-js:0.8.0:*:*:*:*:node.js:*:*
ua-parser-js_project ua-parser-js 1.0.0 cpe:2.3:a:ua-parser-js_project:ua-parser-js:1.0.0:*:*:*:*:node.js:*:*

References for CVE-2021-4229

URL Tags
https://github.com/advisories/GHSA-pjwm-rvh2-c87w Third Party Advisory
https://github.com/faisalman/ua-parser-js/issues/536 Issue Tracking Patch Third Party Advisory
https://vuldb.com/?id.185453 Third Party Advisory VDB Entry
cvelogic Threat Intelligence