VULNERABILITY DETAILS
I can very easily get into my school Chromebooks with my student email and allow administrative access to all student emails, to allow students full control to the Chromebooks, including me.

VERSION
Chrome Version: 62.0.3202.97 + Stable
Operating System: Chrome OS, 62.0.3202.97, Unknown

REPRODUCTION CASE
It is on chrome OS. You enter developer mode (Press, Esc + Refresh, then when the Chromebook turns off, hold the keys again, except this time with the power button as well.) Then, press Ctrl + D, press space to disable verification. Wait for it to turn back on, past the explanation point. Then it said, (I don't quite remember, what it said, but it was somewhere close to this.) "Executive Function" With a email sign in, the admin email was at the end, but I entered my student account, I entered my password, then it took me through a Chromebook setup, like it would if it started up for the first time. Once it finished, it said, "Managed by (My student email rather than the staff and facility email.) I signed in with my student email, and it worked, I then had full control over the Chromebook.
 
FOR CRASHES, PLEASE INCLUDE THE FOLLOWING ADDITIONAL INFORMATION
Type of crash: [tab, browser, etc.]
Crash State: [see link above: stack trace *with symbols*, registers,
exception record]
Client ID (if relevant): [see link above]