Posts on the Digital Spy forums and Apple's own support messageboard raised the issue, reporting an inability to connect to wi-fi networks after being redirected to a faulty web page on Apple's site.
DS user interactiv-uk posted: "Has anyone else noticed wifi isn't working - If you try to join a wifi network you are re-routed to apple.com which then comes up with an error and drops your wifi connection!"
The bug was traced to iOS functionality that checks whether a hotspot login, such as those used by public access points, is needed prior to completing a wi-fi connection. Upon initiating a wi-fi connection, iPhones and iPads running iOS 6 check whether they are able to connect to a page on Apple's site - if successful, the connection completes; if not, the user is presented with a hotspot login window.
The page in question began returning "not found" rather than "success" messages shortly after iOS 6 rolled out, causing iPhones and iPads around the world to lose - and be unable to reliably re-establish - connection to wi-fi hotspots.
The issue was fixed at around 8pm Eastern Time (1am Thursday in the UK).