UPDATE: Apple has pulled the iOS 16.5.1(a) update. Reportedly, many apps started giving a warning about not being supported on the Safari browser following the Rapid Security Response update.
In a statement Apple said:
Apple is aware of an issue where this Rapid Security Response might prevent some websites from displaying properly. Rapid Security Response iOS 16.5.1 (b) and iPadOS 16.5.1 (b) will be available soon to address this issue.
Any user who has updated to 16.5.1(a) has the option to downgrade iOS by going to Settings > General > About and tapping on iOS Version. From there tap on Remove Security Update.
Apple has released iOS 16.5.1 (a), the companies second Rapid Security Response update. The company said the update is recommended for all users and it applies important security fixes to iPhones.
Apple Rapid Security Responses
Rapid Security Response updates are a new type of device update Apple introduced alongside iOS 16.2 in December.
Rapid Security Response updates provide users with important security fixes, and they can help mitigate security issues that are being actively exploited or have been reported.
Rapid Security Responses that involve the operating system require the device to restart. On macOS, the updated operating system content may be made available to Safari and its associated processes with just a relaunch of those processes, though a restart is required to make this content broadly available to the rest of the operating system.
Rapid Security Responses don’t adhere to the managed software update delay; however, because they apply only to the latest minor operating system version, if that minor operating system update is delayed, the response is also effectively delayed. If necessary, the user can also remove the responses.
Rapid Security Response updates are designated with a letter to differentiate them from other updates.
Each Rapid Security Response is versioned relative to its base operating system version, starting with “a”, then “b” and so on. Within a line of RSRs, successive RSRs always include the changes from previous RSRs.
Subsequent minor operating system updates include the content from all the RSRs that were issued for the previous operating system version.
iOS 16.5.1(a) Security Fixes
Impact: Processing web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Description: The issue was addressed with improved checks.
iOS 16.5.1(a) Supported Devices
iOS 16.5.1(a) will run on all iPhones from iPhone 8 onwards. To be exact:
iPhone 14 Plus
iPhone 14 Pro
iPhone 14 Pro Max
iPhone 13 mini
iPhone 13 Pro
iPhone 13 Pro Max
iPhone 12 mini
iPhone 12 Pro
iPhone 12 Pro Max
iPhone 11 Pro
iPhone 11 Pro Max
iPhone XS Max
iPhone 8 Plus
iPhone SE (2nd generation or later)
As normal, to update to iOS 16.5.1(a) , go to your iPhone Settings > General > Software Update and install iOS 16.5.1(a) when you can.