Chroot user exit jail

Question

I am using OpenSSH chrootdirectory feature to give access to a user via ssh.

Can this user exit the jail and return to the normal OS environment? Maybe with su?

score 2 · Answer 1 · answered Mar 03 '15 at 18:29

2

No it cannot, it would give them an error. That's the whole point of chroot. They'll be only locked up in a location without being able to go out that location. But if you want tias.

answered Mar 03 '15 at 18:29

VaTo

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score 2 · Accepted Answer · answered Mar 03 '15 at 18:51

If the user does not have root access (or any way to gain it, such as exploiting an insecure setuid program), escaping a chroot jail should be impossible.

With root access, escaping a chroot jail is trivial. In fact, the chroot(2) manpage even gives instructions:

This call does not change the current working directory, so that after the call '.' can be outside the tree rooted at '/'. In particular, the superuser can escape from a "chroot jail" by doing:
   mkdir foo; chroot foo; cd ..

Chroot user exit jail

2 Answers2