Multiple critical vulnerabilities in Mozilla Firefox and Firefox Extended Support Release (ESR), have been addressed in a recent update. These vulnerabilities allow for remote code execution (RCE) at the logged-in user’s level of access, and are currently being exploited “in the wild”. Users are advised to update Mozilla Firefox to 97.0.2 and Firefox ESR to 91.6.1 or later, as soon as possible.
Instructions for updating Firefox on your desktop/laptop can be found here. Please note that as per the instructions, the update has to be downloaded and Firefox has to be restarted. For more information on these vulnerabilities, please see the following MS-ISAC Cybersecurity Advisory.