While most of the changes in iTunes 10.5 are aimed at supporting iOS 5 and iCloud, Apple has also made some significant changes for Windows users. Central is the removal of QuickTime from the installation package, since iTunes is said to no longer require it. In the past some Windows users have complained about being forced to install QuickTime, which can potentially hijack some filetype associations.
In another rare twist, all of the security fixes in v10.5 apply exclusively to Windows. These target holes in CoreFoundation, ColorSync, CoreAudio and CoreMedia, as well TIFF-related vulnerabilities in ImageIO, and potential man-in-the-middle attacks through WebKit, which is used at the iTunes Store. When a new version of iTunes addresses security, Apple normally includes at least some Mac patches.