This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Excel. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of XLS files. The issue results from the lack of proper initialization of a pointer prior to accessing it. An attacker can leverage this vulnerability to execute code in the context of the current process.
Description of the security update for Office 2013: October 13, 2020
Description of the security update for Office 2016: October 13, 2020
Microsoft Excel XLS File Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability
Security Updates for Microsoft Office Products C2R (October 2020)