CVE-2021-23999

Name of the Vulnerable Software and Affected Versions: Firefox versions prior to 88 Firefox ESR versions prior to 78.10 Thunderbird versions prior to 78.10

Description: The issue is related to errors in inherited permissions, which can be exploited by a remote attacker using a specially crafted Blob URL to elevate privileges. If a Blob URL was loaded through unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content.

Recommendations: For Firefox versions prior to 88, update to version 88 or later to resolve the issue. For Firefox ESR versions prior to 78.10, update to version 78.10 or later to resolve the issue. For Thunderbird versions prior to 78.10, update to version 78.10 or later to resolve the issue.