CVE-2021-43533

Name of the Vulnerable Software and Affected Versions Mozilla Firefox versions prior to 94

Description The issue is related to incorrect restriction of visualized layers in the user interface, which can be exploited by a remote attacker to conduct spoofing attacks. When parsing internationalized domain names, high bits of the characters in the URLs were sometimes stripped, resulting in inconsistencies that could lead to user confusion or attacks such as phishing.

Recommendations For versions prior to 94, update to version 94 or later to resolve the issue. As a temporary workaround, consider restricting access to internationalized domain names until the update is applied. Avoid using URLs with internationalized domain names in the affected browser versions until the issue is resolved.