Zero-day vulnerability in Windows

Elevation of privilege
CVE-2017-0263

The vulnerability was used by APT28 team along with another zero-day CVE-2017-0262.

Known malware:

GAMEFISH

Vulnerability details

Advisory: SB2017050908 - Multiple vulnerabilities in Win32.sys in Microsoft Windows

Vulnerable component: Windows

CVE-ID: CVE-2017-0263

CVSSv3 score: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-20 - Improper input validation

Description:

The vulnerability allows a local user to elevate privileges on the system.

The vulnerability exists due to boundary error in Win32k.sys driver. A local user can escalate privileges on the system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note: this vulnerability is being actively exploited.

Public Exploits:

- Microsoft Window Manager (Windows 7 x86) - Menu Management Component UAF Privilege Elevation [Exploit-DB]

External links:

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0263
https://www.fireeye.com/blog/threat-research/2017/05/eps-processing-zero-days.html
https://blogs.technet.microsoft.com/msrc/2017/05/09/coming-together-to-address-encapsulated-postscri...

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.