CVE-2020-1069

A remote code execution vulnerability exists in Microsoft SharePoint Server when it fails to properly identify and filter unsafe ASP.Net web controls. An authenticated attacker who successfully exploited the vulnerability could use a specially crafted page to perform actions in the security context of the SharePoint application pool process.
To exploit the vulnerability, an authenticated user must create and invoke a specially crafted page on an affected version of Microsoft SharePoint Server.
The security update addresses the vulnerability by correcting how Microsoft SharePoint Server handles processing of created content.