CVE-2023-4736 (Other, published 2023-09-02T19:15Z)
Description: value: Untrusted Search Path in GitHub repository vim/vim prior to 9.0.1833.
Severity: nan (CVSS v3 base score: 7.8)
Weakness: CWE-426 \u2014 Untrusted Search Path
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.
Repository: https://github.com/vim/vim
Files changed:
runtime/autoload/gzip.vim
runtime/autoload/zip.vim
runtime/ftplugin/perl.vim
runtime/ftplugin/ruby.vim
runtime/ftplugin/zig.vim
src/version.c
Commit message: patch 9.0.1833: [security] runtime file fixes

Problem:  runtime files may execute code in current dir
Solution: only execute, if not run from current directory

The perl, zig and ruby filetype plugins and the zip and gzip autoload
plugins may try to load malicious executable files from the current
working directory.  This is especially a problem on windows, where the
current directory is implicitly in your $PATH and windows may even run a
file with the extension `.bat` because of $PATHEXT.

So make sure that we are not trying to execute a file from the current
directory. If this would be the case, error out (for the zip and gzip)
plugins or silently do not run those commands (for the ftplugins).

This assumes, that only the current working directory is bad. For all
other directories, it is assumed that those directories were
intentionally set to the $PATH by the user.

Signed-off-by: Christian Brabandt <cb@256bit.org>


Vulnerable code:
    exe "let s:have_" . name . "=" . e
    if executable("perl")
if !exists('b:ruby_version') && !exists('g:ruby_path') && isdirectory(expand('%:p:h'))
  let s:version_file = findfile('.ruby-version', '.;')
  if !empty(s:version_file) && filereadable(s:version_file)
    let b:ruby_version = get(readfile(s:version_file, '', 1), '')
    if !has_key(g:ruby_version_paths, b:ruby_version)
      let g:ruby_version_paths[b:ruby_version] = s:query_path(fnamemodify(s:version_file, ':p:h'))
endif
if exists("g:ruby_path")
  let s:ruby_path = type(g:ruby_path) == type([]) ? join(g:ruby_path, ',') : g:ruby_path
elseif has_key(g:ruby_version_paths, get(b:, 'ruby_version', ''))
  let s:ruby_paths = g:ruby_version_paths[b:ruby_version]
  let s:ruby_path = s:build_path(s:ruby_paths)
else
  if !exists('g:ruby_default_path')
    if has("ruby") && has("win32")
      ruby ::VIM::command( 'let g:ruby_default_path = split("%s",",")' % $:.join(%q{,}) )
    elseif executable('ruby') && !empty($HOME)
      let g:ruby_default_path = s:query_path($HOME)
    else
      let g:ruby_default_path = map(split($RUBYLIB,':'), 'v:val ==# "." ? "" : v:val')
  let s:ruby_paths = g:ruby_default_path
  let s:ruby_path = s:build_path(s:ruby_paths)
endif
if stridx(&l:path, s:ruby_path) == -1
  let &l:path = s:ruby_path
endif
if exists('s:ruby_paths') && stridx(&l:tags, join(map(copy(s:ruby_paths),'v:val."/tags"'),',')) == -1
  let &l:tags = &tags . ',' . join(map(copy(s:ruby_paths),'v:val."/tags"'),',')
endif
if !exists('g:zig_std_dir') && exists('*json_decode') && executable('zig')

Fixed code:
    " safety check, don't execute anything from the current directory
    let f = fnamemodify(exepath(name), ":p:h") !=# getcwd()
    if !f
      echoerr "Warning: NOT executing " .. name .. " from current directory!"
    endif
    exe "let s:have_" . name . "=" . (e && f)
if fnamemodify(exepath(g:zip_unzipcmd), ":p:h") ==# getcwd()
 echoerr "Warning: NOT executing " .. g:zip_unzipcmd .. " from current directory!"
 finish
endif
    " safety check: don't execute perl from current directory
    if executable("perl") && fnamemodify(exepath("perl"), ":p:h") != getcwd()
let s:execute_ruby = 1
" Security Check, don't execute ruby from the current directory
if fnamemodify(exepath("ruby"), ":p:h") ==# getcwd()
  let s:execute_ruby = 0
endif

function SetRubyPath()
  if !exists('b:ruby_version') && !exists('g:ruby_path') && isdirectory(expand('%:p:h'))
    let s:version_file = findfile('.ruby-version', '.;')
    if !empty(s:version_file) && filereadable(s:version_file) && s:execute_ruby
      let b:ruby_version = get(readfile(s:version_file, '', 1), '')
      if !has_key(g:ruby_version_paths, b:ruby_version)
	let g:ruby_version_paths[b:ruby_version] = s:query_path(fnamemodify(s:version_file, ':p:h'))
      endif
  if exists("g:ruby_path")
    let s:ruby_path = type(g:ruby_path) == type([]) ? join(g:ruby_path, ',') : g:ruby_path
  elseif has_key(g:ruby_version_paths, get(b:, 'ruby_version', '')) && s:execute_ruby
    let s:ruby_paths = g:ruby_version_paths[b:ruby_version]
    let s:ruby_path = s:build_path(s:ruby_paths)
  else
    if !exists('g:ruby_default_path')
      if has("ruby") && has("win32")
	ruby ::VIM::command( 'let g:ruby_default_path = split("%s",",")' % $:.join(%q{,}) )
      elseif executable('ruby') && !empty($HOME) && s:execute_ruby
	let g:ruby_default_path = s:query_path($HOME)
      else
	let g:ruby_default_path = map(split($RUBYLIB,':'), 'v:val ==# "." ? "" : v:val')
      endif
    let s:ruby_paths = g:ruby_default_path
    let s:ruby_path = s:build_path(s:ruby_paths)
  if stridx(&l:path, s:ruby_path) == -1
    let &l:path = s:ruby_path
  endif
  if exists('s:ruby_paths') && stridx(&l:tags, join(map(copy(s:ruby_paths),'v:val."/tags"'),',')) == -1
    let &l:tags = &tags . ',' . join(map(copy(s:ruby_paths),'v:val."/tags"'),',')
  endif
endfunction

call SetRubyPath()
" Safety check: don't execute zip from current directory
if !exists('g:zig_std_dir') && exists('*json_decode') &&
    \  executable('zig') && fnamemodify(exepath("zig"), ":p:h") != getcwd()
/**/
    1833,