A remote code execution vulnerability exists in the way that Microsoft Graphics Components handle objects in memory. An attacker who successfully exploited the vulnerability could execute arbitrary code on a target system. To exploit the vulnerability, a user would have to open a specially crafted file. The security update addresses the vulnerability by correcting how Microsoft Graphics Components handle objects in memory.
https://www.tenable.com/blog/microsoft-s-august-2020-patch-tuesday-addresses-120-cves-cve-2020-1337
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1561