Windows HTTP.sys Elevation of Privilege Vulnerability

According to the CVSS metric, the attack complexity is high (AC:H). What does this mean for this vulnerability?
An attacker would need specific conditions to be in place (i.e. particular protocol settings, or configurations, etc.) before an attack could succeed, which reduces the likelihood of widespread or opportunistic exploitation.

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
10.0.17763.9121 — https://support.microsoft.com/help/5120238
10.0.20348.5499 — https://support.microsoft.com/help/5120242
10.0.20348.5440 — https://support.microsoft.com/help/5120229
10.0.19044.7663 — https://support.microsoft.com/help/5120249
10.0.26100.33296 — https://support.microsoft.com/help/5120233
10.0.26100.33222 — https://support.microsoft.com/help/5120228
10.0.26200.9168 — https://support.microsoft.com/help/5121003
10.0.26200.9106 — https://support.microsoft.com/help/5120994
10.0.22631.7517 — https://support.microsoft.com/help/5120240
10.0.28000.2704 — https://support.microsoft.com/help/5121000
10.0.14393.9418 — https://support.microsoft.com/help/5120418
6.2.9200.26280 — https://support.microsoft.com/help/5120386
6.3.9600.23338 — https://support.microsoft.com/help/5120385