An issue was discovered in certain Apple products. iOS before 11.2 is affected. Safari before 11.0.2 is affected. iCloud before 7.2 on Windows is affected. iTunes before 12.7.2 on Windows is affected. tvOS before 11.2 is affected. watchOS before 4.2 is affected. The issue involves the "WebKit" component. It allows remote attackers to spoof user-interface information (about whether the entire content is derived from a valid TLS session) via a crafted web site that sends a 401 Unauthorized redirect.
https://usn.ubuntu.com/3551-1/
https://support.apple.com/HT208334
https://support.apple.com/HT208328
https://support.apple.com/HT208327
https://support.apple.com/HT208326