Zero-Day Advisory

Fortinet Discovers Microsoft Office Outlook Remote Code Execution Vulnerability


Fortinet's FortiGuard Labs has discovered a remote code execution vulnerability in Microsoft Outlook.

Microsoft Outlook is a personal information manager, which is a part of the Microsoft Office suite. Although it is used mainly as an email application, it also includes a calendar, task manager, contact manager, note taking, journal, and web browsing.

A remote code execution vulnerability exists in Microsoft Outlook resulting from its failure to properly handle objects in memory. To exploit the vulnerability, a user must open a specially crafted RWZ file with an affected version of Microsoft Outlook. An attacker who successfully exploited the vulnerability could perform actions in the security context of the current user.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Dec 06, 2018
Users should apply the solution provided by Microsoft.


Fortinet reported the vulnerability to Microsoft on September 29, 2018.

Microsoft confirmed the vulnerability on October 8, 2018.

Microsoft patched the vulnerability on December 11, 2018.


This vulnerability was discovered by Yonghui Han 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.