Checkmarx Research Labs has identified a new critical vulnerability in
Internet Explorer (other browsers are probably exposed the same way) that
would allow hackers to easily compromise web applications. Cross-Site
History Manipulation (XSHM) is a newly discovered zero-day attack: attackers
may have been using it for a long time, but the application and security
communities do not know it.

To help major browsers or application developers stop the proliferation of
this exploit, Checkmarx has published a guide to identify and remediate the
vulnerability. It can be downloaded at
http://www.checkmarx.com/CxDownloadRequest.aspx?id=8 

A  POC for IE and Facebook users can be seen here:
http://www.checkmarx.com/Demo/XSHM.aspx In this page, an attacker can easily 
detect whether a user is currently authenticated to the Facebook
application. Interested parties will be able to detect XSHM in samples of
their application by using a free download version of the product.

Thanks,
Alex Roichman
Chief Architect and head of Research labs, Checkmarx Ltd.
Securitylabs@checkmarx.com