Cross-site scripting (XSS) vulnerability in WebKit in Apple Safari before 5.0.6 allows remote attackers to inject arbitrary web script or HTML via vectors involving a URL that contains a username.
Apple Security Advisory 2011-10-12-1 - An iOS 5 software update is now available. It addresses an SSL check in CalDAV, a script injection issue in Calendar, issues in CFNetwork, and 90+ other security issues.