An information disclosure vulnerability exists when Microsoft Excel improperly discloses the contents of its memory. An attacker who exploited the vulnerability could use the information to compromise the user’s computer or data. To exploit the vulnerability, an attacker could craft a special document file and then convince the user to open it. An attacker must know the memory address location where the object was created. The update addresses the vulnerability by changing the way certain Excel functions 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-2020-1497