Zero-Day Advisory

Fortinet Discovers Microsoft Windows Kernel Win32k Privilege Elevation Vulnerability


Fortinet's FortiGuard Labs has discovered a Privilege Elevation vulnerability in the Windows kernel subsystem component namely win32k.sys.

The Windows kernel subsystem component is a crucial Windows kernel driver that allows user-mode application to communicate with graphics drivers through kernel-mode graphics device interface provided by this component.

The successful exploitation of the vulnerability could allow an attacker to run code with elevated privileges or cause the target system to stop responding.


Users should apply the solution provided by Microsoft.

Additional Information

Fortinet reported the vulnerability to Microsoft on April 18, 2016.

Microsoft patched the vulnerability on August 9, 2016.


This vulnerability was discovered by Wayne Low of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.