Having problems with file sharing after installing the macOS High Sierra 'root' Security Update? Here's the fix!

How to download and install macOS 10.13.1 on your Mac
How to download and install macOS 10.13.1 on your Mac

Update: Apple has pushed out a new version of the root patch, build 17B1002, which appears to fix the file sharing bug. If you don't think you got the updated patch or you're still experiencing file sharing issues, try the fix below.

The recent "root" vulnerability in macOS High Sierra made waves recently because of its wide-reaching security issue. Apple quickly released a security update to fix the issue in record time, but in its haste, may have accidentally caused an annoying, though not security related, bug for some people attempting to file share on Mac. If you are trying to share files on your Mac after installing the security update, Apple has published a help document (opens in new tab) to fix the issue. Here are the steps.

If you experience issues with authenticating or connecting to file shares on your Mac after you install Security Update 2017-001 for macOS High Sierra 10.13.1, follow these steps to repair file sharing:

  1. Open the Terminal app, which is in the Utilities folder of your Applications folder.
  2. Type sudo /usr/libexec/configureLocalKDC and press Return.
  3. Enter your administrator password and press Return.
  4. Quit the Terminal app.

You should now be able to share files on your Mac without issue.

Lory Gil

Lory is a renaissance woman, writing news, reviews, and how-to guides for iMore. She also fancies herself a bit of a rock star in her town and spends too much time reading comic books.  If she's not typing away at her keyboard, you can probably find her at Disneyland or watching Star Wars (or both).

  • Well, should I install Security Update 2017-001 or should I wait for a new bug-free update? I am not in a rush and I do not share my laptop with others, anyway.
  • I think a security update is far more important than a bug. There's a fix anyway :)
  • Killing file sharing is worse than an exploit that requires physical access to your machine if you rely on your mac for business purposes. It would be a major annoyance if you use your mac for anything else.
  • New update available in the App Store this morning.
  • Hey after the update I turned on my computer and almost all the app icons are missing and they are just a pencil with a ruler and paintbrush. Anyone know how to fix this? and what happened? Thanks
  • Update: I deleted com.apple.dock.plist under library and preferences and restarted the computer and now the icons are there. For anyone else this happened to I am sharing with you. Thanks