If Software Update isn’t your preferred method of installing updates, you can find both updates on the Support Downloads page.
QuickTime 7.6.2 for Leopard is 57MB and for Tiger 48MB. iTunes 8.2 weighs in at 72MB. As with any software update, you should make sure 10% of your hard drive space is available, so you don’t run into any space problems.
iTunes Security and Compatibility Update
According to the iTunes 8.2 for Mac page, the update adds compatibility support for the iPhone and iPod touch and the iPhone 3.0 Software Update. It also includes a number of unspecified accessibility improvements and bug fixes.
A security issue that plugs a hole is also addressed, in case you visit a “maliciously crafted website [that] may lead to unexpected application termination or arbitrary code execution.” The Security Content of iTunes 8.2 page claims a stack buffer overflow is fixed through improved bounds checking.
One note of caution, make sure that if you use an external drive to store your iTunes library, that you have the drive mounted before applying the update. One user reported on MacinTouch that he experienced the dreaded exclamation points of not found songs when he neglected to mount his drive prior to the update.
QuickTime Security Updates
The plugged security issues for QuickTime are more numerous, with ten vulnerabilities fixed, and while much of the page is aimed for the more technical minded, rest assured that there are no reported exploits of these bugs. Apple’s page, About the security content of QuickTime 7.6.2. details the fixes.
According to the IDG News Service, “one flaw — a bug in the way QuickTime reads files that are compressed using the JPEG 2000 (JP2) compression standard — was partially disclosed in Charlie Miller and Dino Dai Zovi’s book, The Mac Hacker’s Handbook, released in March.” So much for that notion that by the time hardcover books are published they’re out of date!