Zero-Day Advisory

Fortinet Discovers Hangul Word Processor Heap Overflow Vulnerability


Fortinet's FortiGuard Labs has discovered a Heap Overflow vulnerability in Hancom's Hangul Word Processor.

Hangul is a proprietary word processing application published by the South Korean company Hancom Inc.. Hangul's specialized support for the Korean written language has gained it widespread use in South Korea, especially by the government.

A Heap Overflow vulnerability has been discovered in Hangul Word Processor due to an uninitialized variable in Hwpapp.dll. It may cause a remote code execution or denial of service on the vulnerable application.


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

Released Jul 04, 2016

Users should apply the solution provided by Hancom.

Additional Information

Fortinet reported the vulnerability to Hancom on February 29, 2016.

Hancom patched the vulnerability on July 4, 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.