Microsoft Windows Vista SP2 up to Server 2012 R2 Kernel win32k.sys access control

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability has been found in Microsoft Windows Vista SP2 up to Server 2012 R2 (Operating System) and classified as critical. Affected by this vulnerability is some unknown functionality in the library win32k.sys of the component Kernel. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-264. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was presented 06/14/2016 as MS16-073 as confirmed bulletin (Technet). It is possible to read the advisory at This vulnerability is known as CVE-2016-3221 since 03/15/2016. The exploitation appears to be easy. The attack can be launched remotely. A single authentication is required for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/23/2022). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The advisory points out:

Multiple elevation of privilege vulnerabilities exist in Windows when the Windows kernel-mode driver fails to properly handle objects in memory. An attacker who successfully exploited the vulnerabilities could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

The vulnerability scanner Nessus provides a plugin with the ID 91601 (MS16-073: Security Update for Windows Kernel-Mode Drivers (3164028)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins. The commercial vulnerability scanner Qualys is able to test this issue with plugin 91236 (Microsoft Windows Kernel Mode Drivers Elevation of Privilege Vulnerabilities (MS16-073)). The advisory illustrates:

To exploit the vulnerabilities, an attacker would first have to log on to the target system. An attacker could then run a specially crafted application that could exploit the vulnerabilities and take control over an affected system. The update addresses the vulnerabilities by correcting how the Windows kernel-mode driver handles objects in memory.

Applying the patch MS16-073 is able to eliminate this problem. The bugfix is ready for download at A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (91601).







CPE 2.3info

CPE 2.2info


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VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.1

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
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NVD Base Score: 7.8
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Class: Access control
CWE: CWE-264

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

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Nessus ID: 91601
Nessus Name: MS16-073: Security Update for Windows Kernel-Mode Drivers (3164028)
Nessus File: 🔍
Nessus Family: 🔍

OpenVAS ID: 802074
OpenVAS Name: Microsoft Kernel-Mode Drivers Privilege Elevation Vulnerabilities (3164028)
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Threat Intelligenceinfo

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Recommended: Patch
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Patch: MS16-073


03/15/2016 🔍
06/14/2016 +91 days 🔍
06/14/2016 +0 days 🔍
06/15/2016 +1 days 🔍
06/16/2016 +1 days 🔍
08/23/2022 +2259 days 🔍



Advisory: MS16-073
Status: Confirmed

CVE: CVE-2016-3221 (🔍)

SecurityTracker: 1036109

scip Labs:


Created: 06/16/2016 04:35 PM
Updated: 08/23/2022 06:49 PM
Changes: 06/16/2016 04:35 PM (68), 04/07/2017 01:38 PM (9), 08/23/2022 06:49 PM (4)
Complete: 🔍
Cache ID: 100:8B6:40


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