Mercurial > vim
view src/vimtutor @ 33664:06b59278bfcf v9.0.2070
patch 9.0.2070: [security] disallow setting env in restricted mode
Commit: https://github.com/vim/vim/commit/6b89dd6a7257a1e2e9c7ea070b407bc4674a5118
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Oct 26 22:14:17 2023 +0200
patch 9.0.2070: [security] disallow setting env in restricted mode
Problem: [security] disallow setting env in restricted mode
Solution: Setting environment variables in restricted mode could
potentially be used to execute shell commands. Disallow this.
restricted mode: disable allow setting of environment variables
Setting environment variables in restricted mode, may have some unwanted
consequences. So, for example by setting $GCONV_PATH in restricted mode
and then calling the iconv() function, one may be able to execute some
unwanted payload, because the `iconv_open()` function internally uses
the `$GCONV_PATH` variable to find its conversion data.
So let's disable setting environment variables, even so this is no
complete protection, since we are not clearing the existing environment.
I tried a few ways but wasn't successful :(
One could also argue to disable the iconv() function completely in
restricted mode, but who knows what other API functions can be
influenced by setting some other unrelated environment variables.
So let's leave it as it is currently.
closes: #13394
See: https://huntr.com/bounties/b0a2eda1-459c-4e36-98e6-0cc7d7faccfe/
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Thu, 26 Oct 2023 22:30:03 +0200 |
parents | d4faa2c5211b |
children |
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#!/bin/sh # Start Vim on a copy of the tutor file. # Usage: vimtutor [-g] [xx] # Where optional argument -g starts vimtutor in gvim (GUI) instead of vim. # and xx is a language code like "es" or "nl". # When an argument is given, it tries loading that tutor. # When this fails or no argument was given, it tries using 'v:lang' # When that also fails, it uses the English version. # Vim could be called "vim" or "vi". Also check for "vimN", for people who # have Vim installed with its version number. # We anticipate up to a future Vim 8.1 version :-). seq="vim vim81 vim80 vim8 vim74 vim73 vim72 vim71 vim70 vim7 vim6 vi" if test "$1" = "-g"; then # Try to use the GUI version of Vim if possible, it will fall back # on Vim if Gvim is not installed. seq="gvim gvim81 gvim80 gvim8 gvim74 gvim73 gvim72 gvim71 gvim70 gvim7 gvim6 $seq" shift fi xx=$1 export xx # We need a temp file for the copy. First try using a standard command. tmp="${TMPDIR-/tmp}" TUTORCOPY=`mktemp $tmp/tutorXXXXXX || tempfile -p tutor || echo none` # If the standard commands failed then create a directory to put the copy in. # That is a secure way to make a temp file. if test "$TUTORCOPY" = none; then tmpdir=$tmp/vimtutor$$ OLD_UMASK=`umask` umask 077 getout=no mkdir $tmpdir || getout=yes umask $OLD_UMASK if test $getout = yes; then echo "Could not create directory for tutor copy, exiting." exit 1 fi TUTORCOPY=$tmpdir/tutorcopy touch $TUTORCOPY TODELETE=$tmpdir else TODELETE=$TUTORCOPY fi export TUTORCOPY # remove the copy of the tutor on exit trap "rm -rf $TODELETE" 0 1 2 3 9 11 13 15 for i in $seq; do testvim=$(which $i 2>/dev/null) if test -f "$testvim"; then VIM=$i break fi done # When no Vim version was found fall back to "vim", you'll get an error message # below. if test -z "$VIM"; then VIM=vim fi # Use Vim to copy the tutor, it knows the value of $VIMRUNTIME # The script tutor.vim tells Vim which file to copy $VIM -f -u NONE -c 'so $VIMRUNTIME/tutor/tutor.vim' # Start vim without any .vimrc, set 'nocompatible' and 'showcmd' $VIM -f -u NONE -c "set nocp showcmd" "$TUTORCOPY"