Updating to i Tunes 12.9 is not possible on OS X Yosemite, as that version is only compatible with mac OS Mojave.Apple Safari is Apple's web browser that comes bundled with the most recent mac OS.
It took multiple calls to Apple Support, where one tech asked me why bother with my beloved 17" MBP, -just go buy a new laptop! What Apple has done with this latest version is a complete disgrace, and they should be ashamed of themselves!
Check with the developer to make sure Safari works with this version of Mac OS X. Be sure to sure to install any available updates for the application and Mac OS X.
One user on Stack Exchange believes that the i Tunes 12.8.1 update may update the Mobile Device.framework in /System/Library/Private Frameworks/ to a version incompatible with Safari 10.1.2, but the cause is not entirely clear.
The vulnerability exists in ALL versions of Safari 12 through 12.0.2.
It has been patched in the current version of Safari Technology Preview, Release 71 (Safari 12.1, Web Kit 14607.1.15).