This vulnerability was reported by Anton Ivanov and Alexey Kulaev of Kaspersky Lab. This vulnerability was used in Operation WizardOpium campaign against Korean users.
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 - Improper Restriction of Operations within the Bounds of a Memory Buffer
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error when processing objects in memory within the Win32k component. A local user can create a malicious application, launch it on the system and execute arbitrary code with SYSTEM privileges.
Note, this vulnerability is being actively exploited in the wild.
Known APT campaigns: