This is catastrophic in terms of the privilege escalation threat/impact to Apple endpoints running High Sierra.
It does have a patch coming, and there is s work round(set root password - highly recommended).
More details alvailble here:
http://www.theregister.co.uk/2017/11/28/root_access_bypass_macos_high_sierra/
Looks like the original link is broken or was changed, thank you for sharing.
https://www.theregister.co.uk/2017/11/29/apple_macos_high_sierra_root_bug_patch/
Something strange is going on with this patch. I applied it yesterday after reading this post (thanks again) and this morning it installed again.
Yes thank you. One wonders if the 'root_access_bypass_macos_high_sierra' but of the URL sounded too much like a useful feature?