Zero-Day Advisory

Fortinet Discovers Microsoft Windows JET Database Engine Buffer Overflow Vulnerability


Fortinet's FortiGuard Labs has discovered a buffer overflow vulnerability in the Microsoft JET Database Engine.

The Microsoft JET Database Engine is a database engine on which several Microsoft products have been built. A database engine is the underlying component of a database, a collection of information stored on a computer in a systematic way.

The buffer overflow vulnerability in the Microsoft JET Database Engine could allow remote code execution on an affected system. An attacker who successfully exploited this vulnerability could take control of an affected system. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. To exploit the vulnerability, a user must open a specially crafted Excel file while using an affected version of Microsoft Windows.


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

Released May 31, 2018

Users should apply the solution provided by Microsoft.


Fortinet reported the vulnerability to Microsoft on June 14, 2018.

Microsoft confirmed the vulnerability on July 18, 2018.

Microsoft patched the vulnerability on September 11, 2018.


This vulnerability was discovered by Honggang Ren 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.