Commit: runtime: don't execute external commands when loading ftplugins

[Christian Brabandt]

runtime: don't execute external commands when loading ftplugins

Commit: https://github.com/vim/vim/commit/f7ac0ef5098856bedca26e7073594a407c05636f
Author: Christian Brabandt <c...@256bit.org>
Date: Wed Sep 6 20:41:25 2023 +0200

runtime: don't execute external commands when loading ftplugins

This is a followup to 816fbcc262687b81fc46f82f7bbeb1453addfe0c (patch
9.0.1833: [security] runtime file fixes)

It basically disables that external commands are run on loading of the
filetype plugin, **unless** the user has set the `g:plugin_exec = 1`
global variable in their configuration or for a specific filetype the
variable g:<filetype>_exec=1.

There are a few more plugins, that may execute system commands like
debchangelog, gitcommit, sh, racket, zsh, ps1 but those do at least
do not run those commands by default during loading of the filetype plugin
(there the command is mostly run as convenience for auto-completion or
to provide documentation lookup).

closes: #13034

Signed-off-by: Christian Brabandt <c...@256bit.org>
Co-authored-by: Tim Pope <v...@tpope.org>

diff --git a/runtime/doc/filetype.txt b/runtime/doc/filetype.txt
index 05047224f..9c092673f 100644
--- a/runtime/doc/filetype.txt
+++ b/runtime/doc/filetype.txt
@@ -1,4 +1,4 @@
-*filetype.txt* For Vim version 9.0. Last change: 2023 Apr 29
+*filetype.txt* For Vim version 9.0. Last change: 2023 Sep 06


VIM REFERENCE MANUAL by Bram Moolenaar
@@ -419,11 +419,24 @@ ways to change this:
3. Docs for the default filetype plugins. *ftplugin-docs*


+ *plugin_exec* *g:plugin_exec*
+Enable executing of external commands. This was done historically for e.g.
+the perl filetype plugin (and a few others) to set the search path.
+Disabled by default for security reasons: >
+ :let g:plugin_exec = 1
+It is also possible to enable this only for certain filetypes: >
+ :let g:<filetype>_exec = 1
+So to enable this only for ruby, set the following variable: >
+ :let g:ruby_exec = 1
+
+If both, the global `plugin_exec` and the `<filetype>_exec` specific variable
+are set, the filetpe specific variable should have precedent.
+
AWK *ft-awk-plugin*

Support for features specific to GNU Awk, like @include, can be enabled by
setting: >
- let g:awk_is_gawk = 1
+ :let g:awk_is_gawk = 1


CHANGELOG *ft-changelog-plugin*
diff --git a/runtime/ftplugin/awk.vim b/runtime/ftplugin/awk.vim
index 1bca3ad3c..785088ff9 100644
--- a/runtime/ftplugin/awk.vim
+++ b/runtime/ftplugin/awk.vim
@@ -37,11 +37,14 @@ if exists("g:awk_is_gawk")
let b:undo_ftplugin .= " | setl fp<"
endif

- let path = system("gawk 'BEGIN { printf ENVIRON[\"AWKPATH\"] }'")
- let path = substitute(path, '^\.\=:\|:\.\=$\|:\.\=:', ',,', 'g') " POSIX cwd
- let path = substitute(path, ':', ',', 'g')
+ " Disabled by default for security reasons.
+ if get(g:, 'awk_exec', get(g:, 'plugin_exec', 0))
+ let path = system("gawk 'BEGIN { printf ENVIRON[\"AWKPATH\"] }'")
+ let path = substitute(path, '^\.\=:\|:\.\=$\|:\.\=:', ',,', 'g') " POSIX cwd
+ let path = substitute(path, ':', ',', 'g')

- let &l:path = path
+ let &l:path = path
+ endif
let b:undo_ftplugin .= " | setl inc< path<"
endif

diff --git a/runtime/ftplugin/changelog.vim b/runtime/ftplugin/changelog.vim
index e9df63f8c..a62433378 100644
--- a/runtime/ftplugin/changelog.vim
+++ b/runtime/ftplugin/changelog.vim
@@ -55,13 +55,19 @@ if &filetype == 'changelog'
elseif $EMAIL_ADDRESS != ""
return $EMAIL_ADDRESS
endif
+ let s:default_login = 'unknown'

- let login = s:login()
+ " Disabled by default for security reasons.
+ if get(g:, 'changelog_exec', get(g:, 'plugin_exec', 0))
+ let login = s:login()
+ else
+ let login = s:default_login
+ endif
return printf('%s <%s@%s>', s:name(login), login, s:hostname())
endfunction

function! s:login()
- return s:trimmed_system_with_default('whoami', 'unknown')
+ return s:trimmed_system_with_default('whoami', s:default_login)
endfunction

function! s:trimmed_system_with_default(command, default)
@@ -71,7 +77,7 @@ if &filetype == 'changelog'
function! s:system_with_default(command, default)
let output = system(a:command)
if v:shell_error
- return default
+ return a:default
endif
return output
endfunction
diff --git a/runtime/ftplugin/perl.vim b/runtime/ftplugin/perl.vim
index 4361097f3..f3de81deb 100644
--- a/runtime/ftplugin/perl.vim
+++ b/runtime/ftplugin/perl.vim
@@ -54,10 +54,12 @@ endif

" Set this once, globally.
if !exists("perlpath")
- " safety check: don't execute perl from current directory
let s:tmp_cwd = getcwd()
- if executable("perl") && (fnamemodify(exepath("perl"), ":p:h") != s:tmp_cwd
- \ || (index(split($PATH,has("win32")? ';' : ':'), s:tmp_cwd) != -1 && s:tmp_cwd != '.'))
+ " safety check: don't execute perl binary by default
+ if executable("perl") && get(g:, 'perl_exec', get(g:, 'plugin_exec', 0))
+ \ && (fnamemodify(exepath("perl"), ":p:h") != s:tmp_cwd
+ \ || (index(split($PATH, has("win32") ? ';' : ':'), s:tmp_cwd) != -1
+ \ && s:tmp_cwd != '.'))
try
if &shellxquote != '"'
let perlpath = system('perl -e "print join(q/,/,@INC)"')
@@ -73,7 +75,7 @@ if !exists("perlpath")
" current directory and the directory of the current file.
let perlpath = ".,,"
endif
- unlet s:tmp_cwd
+ unlet! s:tmp_cwd
endif

" Append perlpath to the existing path value, if it is set. Since we don't
diff --git a/runtime/ftplugin/ruby.vim b/runtime/ftplugin/ruby.vim
index a424801cd..b61c1765d 100644
--- a/runtime/ftplugin/ruby.vim
+++ b/runtime/ftplugin/ruby.vim
@@ -61,6 +61,10 @@ if !exists('g:ruby_version_paths')
endif

function! s:query_path(root) abort
+ " Disabled by default for security reasons.
+ if !get(g:, 'ruby_exec', get(g:, 'plugin_exec', 0))
+ return []
+ endif
let code = "print $:.join %q{,}"
if &shell =~# 'sh' && empty(&shellxquote)
let prefix = 'env PATH='.shellescape($PATH).' '
@@ -84,7 +88,7 @@ function! s:query_path(root) abort
else
let path = split(system(path_check),',')
endif
- unlet s:tmp_cwd
+ unlet! s:tmp_cwd
exe cd cwd
return path
finally
diff --git a/runtime/ftplugin/zig.vim b/runtime/ftplugin/zig.vim
index 45ea58261..2a081980c 100644
--- a/runtime/ftplugin/zig.vim
+++ b/runtime/ftplugin/zig.vim
@@ -40,17 +40,17 @@ endif
let &l:define=' (<fn>|<const>|<var>|^\s*\#\s*define)'

" Safety check: don't execute zip from current directory
-let s:tmp_cwd = getcwd()
if !exists('g:zig_std_dir') && exists('*json_decode') &&
- \ executable('zig') && (fnamemodify(exepath("zig"), ":p:h") != s:tmp_cwd
- \ || (index(split($PATH,has("win32")? ';' : ':'), s:tmp_cwd) != -1 && s:tmp_cwd != '.'))
+ \ executable('zig') && get(g:, 'zig_exec', get(g:, 'plugin_exec', 0))
+ \ && (fnamemodify(exepath("zig"), ":p:h") != s:tmp_cwd
+ \ || (index(split($PATH,has("win32")? ';' : ':'), s:tmp_cwd) != -1 && s:tmp_cwd != '.'))
silent let s:env = system('zig env')
if v:shell_error == 0
let g:zig_std_dir = json_decode(s:env)['std_dir']
endif
unlet! s:env
endif
-unlet s:tmp_cwd
+unlet! s:tmp_cwd

if exists('g:zig_std_dir')
let &l:path = &l:path . ',' . g:zig_std_dir