Windows Layer 2 Tunneling Protocol (L2TP) Remote Code Execution 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 invest time in repeated exploitation attempts through sending constant or intermittent data.

Security updates
10.0.17763.3165 — https://support.microsoft.com/help/5015811
10.0.19043.1826 — https://support.microsoft.com/help/5015807
10.0.20348.825 — https://support.microsoft.com/help/5015827
10.0.22000.795 — https://support.microsoft.com/help/5015814
10.0.10240.19360 — https://support.microsoft.com/help/5015832
10.0.14393.5246 — https://support.microsoft.com/help/5015808
6.1.7601.26022 — https://support.microsoft.com/help/5015861
6.1.7601.26022 — https://support.microsoft.com/help/5015862
6.3.9600.20478 — https://support.microsoft.com/help/5015874
6.3.9600.20478 — https://support.microsoft.com/help/5015877
6.0.6003.21569 — https://support.microsoft.com/help/5015866
6.0.6003.21569 — https://support.microsoft.com/help/5015870
6.2.9200.23771 — https://support.microsoft.com/help/5015863
6.2.9200.23771 — https://support.microsoft.com/help/5015875