4.3
CVSSv2

CVE-2021-23986

Published: 31/03/2021 Updated: 06/08/2021
CVSS v2 Base Score: 4.3 | Impact Score: 2.9 | Exploitability Score: 8.6
CVSS v3 Base Score: 6.5 | Impact Score: 3.6 | Exploitability Score: 2.8
VMScore: 383
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N

Vulnerability Summary

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.

Vulnerability Trend

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mozilla firefox

Vendor Advisories

Mozilla Foundation Security Advisory 2021-10 Security Vulnerabilities fixed in Firefox 87 Announced March 23, 2021 Impact high Products Firefox Fixed in Firefox 87 ...
A security issue was found in Firefox before version 87 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 hav ...