CVE-2021-23986

Medium

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.

SeverityMedium
CVSS6.5
Exploit probability—
ProductMozilla Firefox
PublishedMar 31, 2021
First seenMar 31, 2021

How to fix

Update
  • mozilla firefox87.0 or later

Affected products

ProductAffected versionsFixed in
mozilla firefoxv < 87.087.0

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