Would you provide a reference for this? Searching for "Safari permanent website data bug" didn't lead me to any definitive conclusion as to what you mean.
Website data is viewable in Settings> Safari> Advanced> Website Data. Some items won't delete even if they appear so, when you check again you'll see them return. This is especially onerous considering Apple's stance on privacy.
This happens even with private browsing on both iOS and OSX
Thanks for the reference. Given the changes Apple highlights in iOS 11, I'm surprised this wasn't addressed.
I'd be interested in reading a more technical, in depth piece on the issue looking at it from both the client and the server side (to determine exactly what is potentially available to an attacker). Browsing through 17 pages of user-submitted forum content isn't something I have a lot of patience for (though I suspect that's a reflection more of how little I am (perhaps naïvely) concerned about it).
