RHEL6-ksh_restricted.md

Redhat 6 - Restricted Korn Shell

Restricted Korn Shell

Assuming that ksh is installed. If not yum install ksh Create the link

ln -sf /bin/ksh93 /bin/rksh

Make the login shell of the user point to /bin/rksh i.e.

usermod -s /bin/rksh username

The user will not have now access to

• Change the current working directory
• Set the value of the SHELL, ENV, or PATH variables
• Specify the pathname of a command containing a / (slash)
• Redirect output of a command with > (right caret), >| (right caret, pipe symbol), <> (left caret, right caret), or >> (two right carets).

Avoid vi and awk and lang hacking and remove ls

Edit /etc/kshrc and append at the end of the file the following

if [ “$0” = “-rksh” ]
 then
   alias awk=''
   alias ls=''
   alias python=''
   alias perl=''
   alias vi='rvim'
   alias vim='rvim'
fi