Mark Wilson writes: A few days ago, a serious security flaw with macOS High Sierra came to light. It was discovered that it was possible to log into the 'root' account without entering a password, and -- although the company seemed to have been alerted to the issue a couple of weeks back -- praise was heaped on Apple for pushing a fix out of the door quickly. But calm those celebrations. It now transpires that the bug fix has a bug of its own. Upgrade to macOS 10.13.1 and you could well find that the patch is undone. Slow hand clap.