Apple Stops Signing iOS 14.4.2 After Releasing iOS 14.5.1 With Fix for Actively Exploited Security Issues
Following today's release of iOS 14.5.1 and last week's release of iOS 14.5, Apple has stopped signing iOS 14.4.2, the previously available version of iOS 14 released on March 26. With iOS 14.4.2 no longer being signed, it is not possible to downgrade to iOS 14.4.2 from iOS 14.5 or iOS 14.5.1 if you've already updated your iPhone or iPad.
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date.
iOS 14.4.2 was a security update that addressed a vulnerability where processing maliciously crafted web content could lead to universal cross-site scripting. iOS 14.5 released last week addressed a number of security issues, and today's release of iOS 14.5.1 addresses another pair of WebKit issues that may have been actively exploited, so those who have not yet updated should do so.