Just rooted; for anyone trying privilege escalation to root, I believe it was already said it’s a particular binary. Make sure to carefully read all its output, i didn’t notice the thing at first then went on to the next…
No need to search for exploits on the web to execute on the machine.
Fot the steg, you get one part right in your face when you start, then the other one after the low priv shell. Nothing mind blowing though, if you got root anyway just skip it, or do some steg challenge if you really want.