Difference between revisions of "Restricted Shell for SSH Server"

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$ln -s /bin/bash /bin/rbash
 
$ln -s /bin/bash /bin/rbash
 
</pre>
 
</pre>
3. enable rbash by system setting /etc/shells  
+
* enable rbash by system setting /etc/shells  
 
<pre>
 
<pre>
 
$echo '/bin/rbash' >> /etc/shells
 
$echo '/bin/rbash' >> /etc/shells
 
</pre>
 
</pre>
4. set user shell to /bin/rbash
+
* set user shell to /bin/rbash
 
<pre>
 
<pre>
 
$chsh  #set user shell to /bin/rbash
 
$chsh  #set user shell to /bin/rbash
 
</pre>
 
</pre>
5. Disable "chsh" command for users
+
* Disable "chsh" command for users
 
<pre>
 
<pre>
 
$chmod o= /bin/chsh
 
$chmod o= /bin/chsh
 
</pre>
 
</pre>
6. Login as user and test linux commands..
+
* Login as user and test linux commands..
7. Purge tmux and screen Multiplexer!
+
 
 +
* Purge tmux and screen Multiplexer if installed!

Revision as of 15:38, 23 May 2017

If you use SSH Logins you can lock down the Console to a restriced shell with less enabled commands! This does not work with installed tmux or screen, cause Users can break out of rbash!

  • Login as root User on the Server
  • install rbash with:
apt-get install rbash
  • rename bash by:
mv /bin/bash /bin/oldbash
chmod o= /bin/oldbash
  • create a symlink for rbash to bash
$ln -s /bin/bash /bin/rbash
  • enable rbash by system setting /etc/shells
$echo '/bin/rbash' >> /etc/shells
  • set user shell to /bin/rbash
$chsh   #set user shell to /bin/rbash
  • Disable "chsh" command for users
$chmod o= /bin/chsh
  • Login as user and test linux commands..
  • Purge tmux and screen Multiplexer if installed!