VULNERABILITY INTELLIGENCE
CVE-2021-23986
CVSS score6.5 MEDIUM
EPSS probability0.43%
CISA KEVNot currently listed
Published2021-03-31
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Description
A malicious extension with the 'search' permission could have installed a new search engine whose favicon referenced a cross-origin URL. The response to this cross-origin request could have been read by the extension, allowing a same-origin policy bypass by the extension, which should not have cross-origin permissions. This cross-origin request was made without cookies, so the sensitive information disclosed by the violation was limited to local-network resources or resources that perform IP-based authentication. This vulnerability affects Firefox < 87.
Weakness classification
- nvd@nist.gov: CWE-346
Primary references
- security@mozilla.org — Issue Tracking, Permissions Required, Vendor Advisory
- security@mozilla.org — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Permissions Required, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory