Zero-day vulnerability in Windows

Buffer overflow
CVE-2020-17087

This vulnerability was used in a trageted attacks along with the #VU47741 issue in FreeType library to attack users of Google Chrome.

Vulnerability details

Advisory: SB2020103102 - Memory corruption in Windows kernel driver

Vulnerable component: Windows

CVE-ID: CVE-2020-17087

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

Description:

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.

External links:

https://bugs.chromium.org/p/project-zero/issues/detail?id=2104

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.