Zero-Day Advisory

Fortinet Discovers Microsoft Windows LNK Heap Memory Corruption


Fortinet's FortiGuard Labs has discovered heap memory corruption vulnerability on Microsoft Windows Storage API library that is used to process Microsoft Windows LNK files.

Microsoft Windows LNK files operate as Windows Explorer extensions, rather than file system extensions. As a shell extension, .lnk files cannot be used in place of the file except in Windows Explorer, and have other uses in Windows Explorer in addition to use as a shortcut to a local file (or GUID)

The vulnerability in the Microsoft Windows Storage API library allows remote code execution when the victim open a specially crafted Windows LNK files.


Users should apply the solution provided by Microsoft.


Fortinet reported the vulnerability to Microsoft on November 06, 2019

Microsoft confirmed the vulnerability on November 14, 2019

Microsoft released patch for the vulnerability on March 11, 2020


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.