Zero-Day Advisory

Fortinet Discovers Microsoft Windows Splwow64 Elevation of Privilege Vulnerability


Fortinet's FortiGuard Labs has discovered an elevation of privilege vulnerability in Printer driver host application, namely splwow64, that allows adversaries to elevate privilege from low-integrity to medium-integrity

Splwow64 acts as an LPC/ALPC server that can be triggered when a print job is triggered by applications. It exposes a series of commands that can be sent by client applications related to print job operations.

The vulnerability in the splwow64 allow arbitrary program execution under elevated privilege. To exploit the vulnerability, an attacker would first have to log on to the system. Then the attacker could run a specially crafted application that could exploit the vulnerability and take control of the affected system.


Users should apply the solution provided by Microsoft.


Fortinet reported the vulnerability to Microsoft on August 19, 2019.

Microsoft confirmed the vulnerability on September 22, 2019.

Microsoft released patch for the vulnerability on November 13, 2019.


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.