CVE-2021-21317

MediumCVSS 5.3/10Last modified Jun 17, 2026

Description

uap-core in an open-source npm package which contains the core of BrowserScope's original user agent string parser. In uap-core before version 0.11.0, some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings. This is fixed in version 0.11.0. Downstream packages such as uap-python, uap-ruby etc which depend upon uap-core follow different version schemes.

Metrics

CVSS 3.1 5.3/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weakness enumeration

CWE-400 CWE-1333

Affected software

Vendor	Product	Versions
ua-parser	uap-core	< 0.11.0

References

https://github.com/ua-parser/uap-core/commit/dc9925d458214cfe87b93e35346980612f6ae96cPatch
https://github.com/ua-parser/uap-core/security/advisories/GHSA-p4pj-mg4r-x6v4Third Party Advisory
https://www.npmjs.com/package/uap-coreProduct, Third Party Advisory
https://github.com/ua-parser/uap-core/commit/dc9925d458214cfe87b93e35346980612f6ae96cPatch
https://github.com/ua-parser/uap-core/security/advisories/GHSA-p4pj-mg4r-x6v4Third Party Advisory
https://www.npmjs.com/package/uap-coreProduct, Third Party Advisory

Timeline

Published: Feb 16, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-213185.4Opencast is a free, open-source platform to support the management of educational audio and video content. In Opencast before version 9.2 th CVE-2021-213195.4Galette is a membership management web application geared towards non profit organizations. In versions prior to 0.9.5, malicious javascript CVE-2021-213204.3matrix-react-sdk is an npm package which is a Matrix SDK for React Javascript. In matrix-react-sdk before version 3.15.0, the user content s CVE-2021-2132110.0fastify-reply-from is an npm package which is a fastify plugin to forward the current http request to another server. In fastify-reply-from CVE-2021-213229.8fastify-http-proxy is an npm package which is a fastify plugin for proxying your http requests to another server, with hooks. By crafting a CVE-2021-213235.3Brave is an open source web browser with a focus on privacy and security. In Brave versions 1.17.73-1.20.103, the CNAME adblocking feature a CVE-2021-213246.5GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software aud CVE-2021-213254.8GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software aud CVE-2021-213266.5GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software aud CVE-2021-213277.5GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software aud CVE-2021-213285.3Vapor is a web framework for Swift. In Vapor before version 4.40.1, there is a DoS attack against anyone who Bootstraps a metrics backend fo CVE-2021-213299.8RATCF is an open-source framework for hosting Cyber-Security Capture the Flag events. In affected versions of RATCF users with multi factor