Zero-Day Advisory

Fortinet Discovers Microsoft IE hlink.dll Information Disclosure Vulnerability

Summary

Fortinet's FortiGuard Labs has discovered an information disclosure vulnerability in Microsoft Internet Explorer (IE).
IE is one of the most widely used web browsers. It's developed by Microsoft and included as part of the Microsoft Windows operating systems. IE uses a componentized architecture built on the Component Object Model (COM) technology. It consists of several major components, each of which is contained in a separate Dynamic-link library (DLL) and exposes a set of COM programming interfaces.
An information disclosure vulnerability exists in IE when Hyperlink Object Library improperly discloses the contents of its memory. An attacker who successfully exploited this vulnerability could obtain information to further compromise the user's system.

Solutions

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

MS.IE.hlink.WzDupWzToWz.Memory.Corruption
Released Oct 29, 2015

Users should apply the solution provided by Microsoft.

Additional Information

To exploit the vulnerability, an attacker must convince a user to either click a link in an email message or open an Office file, and then click a link in the file.

Acknowledgement

This vulnerability was discovered by Kai Lu 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.