Apple announced today that there's a security hole in the High Sierra update (OSX 10.13). The issue is a blank root password. 
We know that Apple is working on patching this as fast as possible, and we will push through the update as soon as it's available. 
Since this only effects High Sierra, below are instructions to check your version and manually update your root password. Please call ArcLight Support at 617.379.5900 for assistance changing your root password, or follow the below instructions.​

Check your version: 
- Go to the Apple menu, select "About this Mac"
- Only OSX 10.13 is affected

Changing Root Password on Mac OS High Sierra:
Step 1 | Launch System Preferences
Step 2 | Select Users & Groups
Step 3 | Select Login Options
Step 4 | Select Join next to Network Account Server
Step 5 | Select Open Directory Utility
Step 6 | Click the lock and enter your password to make changes
Step 7 | In the menu bar of Directory Utility, select Change Root Password
Step 8 | Create a strong, unique password, and ensure it's one you'll remember!

Cheers,
ArcLight IT