CVE-2021-23986 Information

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.

CVSS Vector

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

Reference

https://www.mozilla.org/security/advisories/mfsa2021-10/ https://bugzilla.mozilla.org/show_bug.cgi?id=1692623

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

6.5