A remote code execution vulnerability exists in the way that Windows handles objects in memory. An attacker who successfully exploited the vulnerability could execute arbitrary code with elevated permissions on a target system. To exploit the vulnerability, an attacker who has a domain user account could create a specially crafted request, causing Windows to execute arbitrary code with elevated permissions. The security update addresses the vulnerability by correcting how Windows handles objects in memory.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1067
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1067