Zero-day vulnerability in Windows

Buffer overflow
CVE-2019-0803

The vulnerability was reported to Microsoft by Donghai Zhu of Alibaba Cloud Intelligence Security Team.

Vulnerability details

Advisory: SB2019040905 - Privilege escalation in Win32k.sys driver in Microsoft Windows

Vulnerable component: Windows

CVE-ID: CVE-2019-0803

CVSSv3 score: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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 privileges on the system.

The vulnerability exists due to a boundary error when processing objects in memory within the Microsoft Graphics 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.

Public Exploits:

- Microsoft Windows - 'Win32k' Local Privilege Escalation [Exploit-DB]

External links:

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0803

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.