5

I'm trying to create the user lenny, that has read and write permissions in the folder /home/lenny/ and has no shell but only access via SFTP. I'm doing the following:

useradd lenny
mkdir /home/lenny
usermod -d /home/lenny lenny
passwd lenny
chown lenny:lenny /home/lenny
chmod 755 /home/lenny
usermod -s /bin/false myuser

I then modified /etc/ssh/sshd_config:

Subsystem sftp internal-sftp`  

Match User lenny
ChrootDirectory /home/lenny
ForceCommand internal-sftp

Now when I do sftp lenny@server I can leave the CHROOT easily by doing cd / and ls -la, I see everything!

Why is that??? I don't get it, configuration should be okay, or am I wrong?

  • Probably, you should add "AllowTcpForwarding no" and "X11Forwarding no" to the "Match User" section. – jofel Apr 19 '12 at 15:41
  • @jofel I tried it with these two settings, it didn't work either. – JohnnyFromBF Apr 19 '12 at 17:13
  • What version of sshd are you running? The version of the ssh package is sufficient. – George M Apr 19 '12 at 17:26
  • @uther It's actually a Kubuntu 11.10 with openssh. Version is 5.8p1-7ubuntu1. – JohnnyFromBF Apr 19 '12 at 18:34
5

Did you restart the sshd service after making the changes to /etc/ssh/sshd_config?

sudo /etc/init.d/ssh restart

Ensure the chroot directory for the sftp user (in this case /home/lenny) is owned by root, not the sftp user. chmod 755 is correct.

Also, I would add the following two lines for additional security:

Match User lenny
    ChrootDirectory /home/lenny
    ForceCommand internal-sftp
    X11Forwarding no
    AllowTcpForwarding no

Restart your sshd service and you should have the desired chroot.

  • Yes, I did a restart and reload, didn't work. – JohnnyFromBF Apr 19 '12 at 17:13
  • See my additional edit. The directory should be owned by root. I missed that the first time and it was staring me in the face. – George M Apr 19 '12 at 18:56
  • Thanks, that solved it! One further question, how can I give lenny read and write permissions below /home/lenny? – JohnnyFromBF Apr 20 '12 at 7:44
  • 2
    So user lenny cannot upload files or create directories in /home/lenny? Make sure /home/lenny group ownership is lenny and chmod 775 /home/lenny. – George M Apr 20 '12 at 15:28

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