Microsoft SharePoint Server Elevation of Privilege Vulnerability

What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker who successfully exploited this vulnerability could gain administrator privileges.

According to the CVSS metric, privileges required is low (PR:L). What does that mean for this vulnerability?
The attacker must be authenticated to the target site as at least a Site Member.

According to the CVSS metric, successful exploitation of this vulnerability could lead to total loss of confidentiality (C:H), integrity (I:H), and availability (A:H). What does that mean for this vulnerability?
An attacker who successfully exploits this vulnerability could perform a remote attack that could enable access to the victim's information and the ability to alter information. Successful exploitation could also potentially cause downtime for the targeted environment.

How could an attacker exploit the vulnerability?
An attacker could exploit the vulnerability by creating an ASP.NET page with specially-crafted declarative markup.

Security updates
16.0.5413.1001 — https://support.microsoft.com/help/5002494
16.0.10402.20016 — https://support.microsoft.com/help/5002472
16.0.16731.20180 — https://support.microsoft.com/help/5002474