CVE-2021-27292

Name: CVE-2021-27292
Creator: NVD / NIST
Published: 2021-03-17T13:15:15.2+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 3.37%

Last modified Jun 17, 2026

CVE-2021-27292 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.. EPSS estimates a 3.37% chance of exploitation in the next 30 days.

Description

ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

3.37%

87.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Ua-Parser-Js Project	Ua-Parser-Js	>= 0.7.14, < 0.7.24

References

https://gist.github.com/b-c-ds/6941d80d6b4e694df4bc269493b7be76Exploit, Third Party Advisory
https://github.com/faisalman/ua-parser-js/commit/809439e20e273ce0d25c1d04e111dcf6011eb566Patch, Third Party Advisory
https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14Patch, Third Party Advisory
https://gist.github.com/b-c-ds/6941d80d6b4e694df4bc269493b7be76Exploit, Third Party Advisory
https://github.com/faisalman/ua-parser-js/commit/809439e20e273ce0d25c1d04e111dcf6011eb566Patch, Third Party Advisory
https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14Patch, Third Party Advisory

Timeline

Published: Mar 17, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27292?

How severe is CVE-2021-27292?

CVE-2021-27292 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 3.37% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27292?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27292?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST