VULNERABILITY INTELLIGENCE

CVE-2021-43540

CVSS score6.5 MEDIUM

EPSS probability0.89%

CISA KEVNot currently listed

Published2021-12-08

Last modified2026-06-17

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

Description

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.

Weakness classification

nvd@nist.gov: NVD-CWE-noinfo

Primary references

security@mozilla.org — Issue Tracking, Permissions Required, Vendor Advisory
security@mozilla.org — Third Party Advisory
security@mozilla.org — Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Permissions Required, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory