#VU1116 Privilege escalation in Windows and Windows Server - CVE-2016-7255
Published: November 1, 2016 / Updated: June 17, 2021
Vulnerability identifier: #VU1116
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Green
CVE-ID: CVE-2016-7255
CWE-ID: CWE-119
Exploitation vector: Local access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Windows
Windows Server
Windows
Windows Server
Software vendor:
Microsoft
Microsoft
Description
The vulnerability allows a local user to gain elevated privileges on the target system.
The weakness is due to improper handling of objects in memory by win32k.sys. By sending a specially crafted system call NtSetWindowLongPtr(), a local attacker can set index GWLP_ID to WS_CHILD value on a window handle with GWL_STYLE and execute arbitrary code with system privileges.
Successful explotation of the vulnerability results in privilege escalation.
Note: this vulnerability is being actively exploited in the wild.
Remediation
Install update from vendor's website.