Fortinet advises that its FortiGate security appliances, FortiMail antispam appliances and FortiClient Host Security software protect against possible malwares exploiting Microsoft Internet Explorer's Msdds.dll vulnerability (Microsoft Security Advisory 906267).

This vulnerability was disclosed on August 17th, 2005, and although a proof-of-concept exploit is publicly available, no vendor patch has been released yet (as of August, 22th 2005). The issue is caused by a flaw in Msdds.dll, a COM object shipped with various Microsoft applications (e.g. some versions of Microsoft Office and Microsoft Visual Studio). A specifically crafted web page instantiating this object could lead to full system compromise upon users viewing it in Internet Explorer.

As of writing, no malware exploiting this flaw has been reported. However, since making use of it would require little user interaction - added to the fact that a proof-of-concept code is publicly available and that no vendor patch is available yet - Fortinet experts estimate that malwares are likely to make use of this vulnerability soon via pointers to malicious webpages.

Fortinet protects against downloading and viewing such webpages as follows:
HTML/Msdds-exploit

Additional info:
Microsoft advisory: http://www.microsoft.com/technet/security/advisory/906267.mspx
FrSIRT Advisory : FrSIRT/ADV-2005-1450
CVE Reference : CAN-2005-2127

For more information on the FortiGuard Network, please visit:
http://www.fortiguardcenter.com

For more information on Fortinet's FortiGate and FortiMail systems and FortiClient Host Security software, please visit:
http://www.fortinet.com/products/