An elevation of privilege vulnerability exists in Windows store installer where WindowsApps directory is vulnerable to symbolic link attack. An attacker who successfully exploited this vulnerability could bypass access restrictions to add or remove files.
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and add or remove files.
The security update addresses the vulnerability by not allowing reparse points in the WindowsApps directory.