Active Template Library Elevation of Privilege Vulnerability

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to take additional actions prior to exploitation to prepare the target environment.

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

Security updates
10.0.17763.4645 — https://support.microsoft.com/help/5028168
10.0.20348.1850 — https://support.microsoft.com/help/5028171
10.0.22000.2176 — https://support.microsoft.com/help/5028182
10.0.19044.3208 — https://support.microsoft.com/help/5028166
10.0.22621.1992 — https://support.microsoft.com/help/5028185
10.0.10240.20048 — https://support.microsoft.com/help/5028186
10.0.14393.6085 — https://support.microsoft.com/help/5028169
6.0.6003.22175 — https://support.microsoft.com/help/5028222
6.0.6003.22175 — https://support.microsoft.com/help/5028226
6.1.7601.26623 — https://support.microsoft.com/help/5028240
6.1.7601.26623 — https://support.microsoft.com/help/5028224
6.2.9200.24374 — https://support.microsoft.com/help/5028232
6.2.9200.24374 — https://support.microsoft.com/help/5028233
6.3.9600.21063 — https://support.microsoft.com/help/5028228
6.3.9600.21075 — https://support.microsoft.com/help/5028223