Summary
The npm package ua-parser-js had three versions published with malicious code. Users of affected versions (0.7.29, 0.8.0, 1.0.0) should upgrade as soon as possible and check their systems for suspicious activity. See this issue for details as they unfold.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Impact
CVE-2021-4229 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.7.30, 0.8.1, 1.0.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
ua-parser-js to 0.7.30 or later; ua-parser-js to 0.8.1 or later; ua-parser-js to 1.0.1 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-4229? CVE-2021-4229 is a high-severity security vulnerability in ua-parser-js (npm), affecting versions = 0.7.29. It is fixed in 0.7.30, 0.8.1, 1.0.1.
- How severe is CVE-2021-4229? CVE-2021-4229 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of ua-parser-js are affected by CVE-2021-4229? ua-parser-js (npm) versions = 0.7.29 is affected.
- Is there a fix for CVE-2021-4229? Yes. CVE-2021-4229 is fixed in 0.7.30, 0.8.1, 1.0.1. Upgrade to this version or later.
- Is CVE-2021-4229 exploitable, and should I be worried? Whether CVE-2021-4229 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2021-4229 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2021-4229?
- Upgrade
ua-parser-jsto 0.7.30 or later - Upgrade
ua-parser-jsto 0.8.1 or later - Upgrade
ua-parser-jsto 1.0.1 or later
- Upgrade