iCloud sync bug was retaining Safari browsing histories


A forensic firm named Elcomsoft released findings that Apple's iCloud was retaining Safari browsing history despite clearing the history on devices.

The Verge:

iCloud used the records to sync browser histories across different devices, a central feature of Safari. Clearing your browsing history on a Mac will also clear it on phones and tablets linked through iCloud, even if the devices are powered down when the request is made. That function typically requires a record that a given site has been visited and cleared. Still, Elcomsoft found those records stored in unhashed form, as far back as November 2015, making them ripe for forensic analysis.

The issue since has been fixed, but seems to be related to synced devices being offline. The history was retained in order to manage the sync of offline devices.

It's worth noting that this feature has to be enabled by the user as part of iCloud's Safari sync. Personally, I wish Apple gave more granular controls over Safari sync. For example, allow syncing of bookmarks, but not history.