At North Carolina State University, researchers have apparently discovered security vulnerabilities in some of the latest, most popular smartphones on the market. These smartphones include the HTC Legend, EVO 4G, and Wildfire S; the Motorola Droid and Droid X; the Samsung Epic 4G; and the Google Nexus One and Nexus S. To be specific, these vulnerabilities are linked to the stock ROMs flashed to these devices by their respective vendors.
Apparently, these vendors have failed to follow one or more permission-based security models set forth by Android. Some of these failures are considered minor, but others are deemed more serious.
You can read more about this here.