Zero-Day Advisory

Fortinet Discovers Vulnerability in Microsoft Internet Explorer 8


Fortinet's FortiGuard Labs has discovered an insecure library loading vulnerability in Microsoft Internet Explorer 8.


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

Released Mar 02, 2011
Users should apply the solution provided by Microsoft.

Additional Information

The vulnerability exists in the way Internet Explorer 8 handles the loading of IEShims.dll. In a successful exploit of this vulnerability, an attacker could gain the same user rights as the logged-on user.


Haifei Li 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.