This vulnerability was used in a trageted attacks along with the #VU47741 issue in FreeType library to attack users of Google Chrome.
Vulnerable component: Windows
CVSSv3 score: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C
CWE-ID: CWE-119 - Memory corruption
The vulnerability allows a local user to escalate privilege son the system.
The vulnerability exists due to a boundary error within the Windows Kernel Cryptography Driver cng.sys, which exposes a "\Device\CNG" device to user-mode programs and supports a variety of IOCTLs with non-trivial input structures. A local user can run a specially crafted program to trigger memory corruption and execute arbitrary code on the system with elevated privileges.
Note, this vulnerability is being actively exploited in the wild.