There are only 10 critical vulnerabilities as part of this release, while there are two moderate-severity exploits. The security updates cover several different products and services, including the Microsoft Defender antivirus software, the Microsoft Remote Procedure Call tools and Bluetooth communication with Windows devices. Talos also released a new set of SNORT rules that provide coverage for some of these vulnerabilities. Users of all Microsoft and Windows products are urged to update their software as soon as possible to avoid possible exploitation of all bugs.”]
Source: https://blog.talosintelligence.com/2021/01/microsoft-patch-tuesday-for-jan-2021.html