vim-patch:9.1.1551: [security]: path traversal issue in zip.vim (#34951)

Problem:  [security]: path traversal issue in zip.vim (@ax)
Solution: drop leading ../ on write of zipfiles, don't forcefully
          overwrite existing files

A zip plugin which contains filenames with leading '../'  may cause
confusion as to where the content will be extracted.  Let's drop such
things and make sure we use a relative filename instead and don't
forcefully overwrite temporary files. Also, warn the user of such
things.

related: vim/vim#17733

586294a041

vim-patch:e1044fb: runtime(zip): raise minimum Vim version to v9.0
vim-patch:e2d9b0d: runtime(zip): zip plugin does not work with Vim 9.0

Co-authored-by: Christian Brabandt <cb@256bit.org>
This commit is contained in:
zeertzjq
2025-07-16 09:08:57 +08:00
committed by GitHub
parent 9789a3b854
commit 5cfdd4d8b9
4 changed files with 98 additions and 60 deletions

View File

@@ -15,6 +15,7 @@
" 2024 Aug 18 by Vim Project: correctly handle special globbing chars
" 2024 Aug 21 by Vim Project: simplify condition to detect MS-Windows
" 2025 Mar 11 by Vim Project: handle filenames with leading '-' correctly
" 2025 Jul 12 by Vim Project: drop ../ on write to prevent path traversal attacks
" License: Vim License (see vim's :help license)
" Copyright: Copyright (C) 2005-2019 Charles E. Campbell {{{1
" Permission is hereby granted to use and distribute this code,
@@ -71,8 +72,9 @@ fun! s:Mess(group, msg)
echohl Normal
endfun
if v:version < 702
call s:Mess('WarningMsg', "***warning*** this version of zip needs vim 7.2 or later")
if !has('nvim-0.10') && v:version < 901
" required for defer
call s:Mess('WarningMsg', "***warning*** this version of zip needs vim 9.1 or later")
finish
endif
" sanity checks
@@ -235,59 +237,62 @@ endfun
" zip#Write: {{{2
fun! zip#Write(fname)
let dict = s:SetSaneOpts()
let need_rename = 0
defer s:RestoreOpts(dict)
" sanity checks
if !executable(substitute(g:zip_zipcmd,'\s\+.*$','',''))
call s:Mess('Error', "***error*** (zip#Write) sorry, your system doesn't appear to have the ".g:zip_zipcmd." program")
return
endif
if !exists("*mkdir")
call s:Mess('Error', "***error*** (zip#Write) sorry, mkdir() doesn't work on your system")
return
call s:Mess('Error', "***error*** (zip#Write) sorry, your system doesn't appear to have the ".g:zip_zipcmd." program")
return
endif
let curdir= getcwd()
let tmpdir= tempname()
if tmpdir =~ '\.'
let tmpdir= substitute(tmpdir,'\.[^.]*$','','e')
let tmpdir= substitute(tmpdir,'\.[^.]*$','','e')
endif
call mkdir(tmpdir,"p")
" attempt to change to the indicated directory
if s:ChgDir(tmpdir,s:ERROR,"(zip#Write) cannot cd to temporary directory")
return
return
endif
" place temporary files under .../_ZIPVIM_/
if isdirectory("_ZIPVIM_")
call delete("_ZIPVIM_", "rf")
call delete("_ZIPVIM_", "rf")
endif
call mkdir("_ZIPVIM_")
cd _ZIPVIM_
if has("unix")
let zipfile = substitute(a:fname,'zipfile://\(.\{-}\)::[^\\].*$','\1','')
let fname = substitute(a:fname,'zipfile://.\{-}::\([^\\].*\)$','\1','')
let zipfile = substitute(a:fname,'zipfile://\(.\{-}\)::[^\\].*$','\1','')
let fname = substitute(a:fname,'zipfile://.\{-}::\([^\\].*\)$','\1','')
else
let zipfile = substitute(a:fname,'^.\{-}zipfile://\(.\{-}\)::[^\\].*$','\1','')
let fname = substitute(a:fname,'^.\{-}zipfile://.\{-}::\([^\\].*\)$','\1','')
let zipfile = substitute(a:fname,'^.\{-}zipfile://\(.\{-}\)::[^\\].*$','\1','')
let fname = substitute(a:fname,'^.\{-}zipfile://.\{-}::\([^\\].*\)$','\1','')
endif
if fname =~ '^[.]\{1,2}/'
call system(g:zip_zipcmd." -d ".s:Escape(fnamemodify(zipfile,":p"),0)." ".s:Escape(fname,0))
let fname = fname->substitute('^\([.]\{1,2}/\)\+', '', 'g')
let need_rename = 1
endif
if fname =~ '/'
let dirpath = substitute(fname,'/[^/]\+$','','e')
if has("win32unix") && executable("cygpath")
let dirpath = substitute(fname,'/[^/]\+$','','e')
if has("win32unix") && executable("cygpath")
let dirpath = substitute(system("cygpath ".s:Escape(dirpath,0)),'\n','','e')
endif
call mkdir(dirpath,"p")
endif
call mkdir(dirpath,"p")
endif
if zipfile !~ '/'
let zipfile= curdir.'/'.zipfile
let zipfile= curdir.'/'.zipfile
endif
exe "w! ".fnameescape(fname)
" don't overwrite files forcefully
exe "w ".fnameescape(fname)
if has("win32unix") && executable("cygpath")
let zipfile = substitute(system("cygpath ".s:Escape(zipfile,0)),'\n','','e')
let zipfile = substitute(system("cygpath ".s:Escape(zipfile,0)),'\n','','e')
endif
if (has("win32") || has("win95") || has("win64") || has("win16")) && &shell !~? 'sh$'
@@ -296,21 +301,24 @@ fun! zip#Write(fname)
call system(g:zip_zipcmd." -u ".s:Escape(fnamemodify(zipfile,":p"),0)." ".s:Escape(fname,0))
if v:shell_error != 0
call s:Mess('Error', "***error*** (zip#Write) sorry, unable to update ".zipfile." with ".fname)
call s:Mess('Error', "***error*** (zip#Write) sorry, unable to update ".zipfile." with ".fname)
elseif s:zipfile_{winnr()} =~ '^\a\+://'
" support writing zipfiles across a network
let netzipfile= s:zipfile_{winnr()}
1split|enew
let binkeep= &binary
let eikeep = &ei
set binary ei=all
exe "noswapfile e! ".fnameescape(zipfile)
call netrw#NetWrite(netzipfile)
let &ei = eikeep
let &binary = binkeep
q!
unlet s:zipfile_{winnr()}
" support writing zipfiles across a network
let netzipfile= s:zipfile_{winnr()}
1split|enew
let binkeep= &binary
let eikeep = &ei
set binary ei=all
exe "noswapfile e! ".fnameescape(zipfile)
call netrw#NetWrite(netzipfile)
let &ei = eikeep
let &binary = binkeep
q!
unlet s:zipfile_{winnr()}
elseif need_rename
exe $"sil keepalt file {fnameescape($"zipfile://{zipfile}::{fname}")}"
call s:Mess('Warning', "***error*** (zip#Browse) Path Traversal Attack detected, dropping relative path")
endif
" cleanup and restore current directory
@@ -319,7 +327,6 @@ fun! zip#Write(fname)
call s:ChgDir(curdir,s:WARNING,"(zip#Write) unable to return to ".curdir."!")
call delete(tmpdir, "rf")
setlocal nomod
endfun
" ---------------------------------------------------------------------
@@ -332,15 +339,18 @@ fun! zip#Extract()
" sanity check
if fname =~ '^"'
return
return
endif
if fname =~ '/$'
call s:Mess('Error', "***error*** (zip#Extract) Please specify a file, not a directory")
return
call s:Mess('Error', "***error*** (zip#Extract) Please specify a file, not a directory")
return
elseif fname =~ '^[.]\?[.]/'
call s:Mess('Error', "***error*** (zip#Browse) Path Traversal Attack detected, not extracting!")
return
endif
if filereadable(fname)
call s:Mess('Error', "***error*** (zip#Extract) <" .. fname .."> already exists in directory, not overwriting!")
return
call s:Mess('Error', "***error*** (zip#Extract) <" .. fname .."> already exists in directory, not overwriting!")
return
endif
let target = fname->substitute('\[', '[[]', 'g')
" unzip 6.0 does not support -- to denote end-of-arguments
@@ -362,13 +372,12 @@ fun! zip#Extract()
" extract the file mentioned under the cursor
call system($"{g:zip_extractcmd} -o {shellescape(b:zipfile)} {target}")
if v:shell_error != 0
call s:Mess('Error', "***error*** ".g:zip_extractcmd." ".b:zipfile." ".fname.": failed!")
call s:Mess('Error', "***error*** ".g:zip_extractcmd." ".b:zipfile." ".fname.": failed!")
elseif !filereadable(fname)
call s:Mess('Error', "***error*** attempted to extract ".fname." but it doesn't appear to be present!")
call s:Mess('Error', "***error*** attempted to extract ".fname." but it doesn't appear to be present!")
else
echomsg "***note*** successfully extracted ".fname
echomsg "***note*** successfully extracted ".fname
endif
endfun
" ---------------------------------------------------------------------

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@@ -111,6 +111,18 @@ Copyright: Copyright (C) 2005-2015 Charles E Campbell *zip-copyright*
==============================================================================
4. History *zip-history* {{{1
unreleased:
Jul 12, 2025 * drop ../ on write to prevent path traversal attacks
Mar 11, 2025 * handle filenames with leading '-' correctly
Aug 21, 2024 * simplify condition to detect MS-Windows
Aug 18, 2024 * correctly handle special globbing chars
Aug 05, 2024 * clean-up and make it work with shellslash on Windows
Aug 05, 2024 * workaround for the FreeBSD's unzip
Aug 04, 2024 * escape '[' in name of file to be extracted
Jul 30, 2024 * fix opening remote zipfile
Jul 24, 2024 * use delete() function
Jul 23, 2024 * fix 'x' command
Jun 16, 2024 * handle whitespace on Windows properly (#14998)
v33 Dec 07, 2021 * `*.xlam` mentioned twice in zipPlugin
v32 Oct 22, 2021 * to avoid an issue with a vim 8.2 patch, zipfile: has
been changed to zipfile:// . This often shows up

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@@ -9,13 +9,14 @@ endif
runtime plugin/zipPlugin.vim
func Test_zip_basic()
"## get our zip file
if !filecopy("samples/test.zip", "X.zip")
call assert_report("Can't copy samples/test.zip")
return
func s:CopyZipFile(source)
if !filecopy($"samples/{a:source}", "X.zip")
call assert_report($"Can't copy samples/{a:source}.zip")
endif
endfunc
func Test_zip_basic()
call s:CopyZipFile("test.zip")
defer delete("X.zip")
e X.zip
@@ -142,11 +143,7 @@ func Test_zip_glob_fname()
CheckNotMSWindows
" does not work on Windows, why?
"## copy sample zip file
if !filecopy("samples/testa.zip", "X.zip")
call assert_report("Can't copy samples/testa.zip")
return
endif
call s:CopyZipFile("testa.zip")
defer delete("X.zip")
defer delete('zipglob', 'rf')
@@ -240,10 +237,7 @@ func Test_zip_fname_leading_hyphen()
CheckNotMSWindows
"## copy sample zip file
if !filecopy("samples/poc.zip", "X.zip")
call assert_report("Can't copy samples/poc.zip")
return
endif
call s:CopyZipFile("poc.zip")
defer delete("X.zip")
defer delete('-d', 'rf')
defer delete('/tmp/pwned', 'rf')
@@ -258,3 +252,26 @@ func Test_zip_fname_leading_hyphen()
call assert_false(filereadable('/tmp/pwned'))
bw
endfunc
func Test_zip_fname_evil_path()
CheckNotMSWindows
" needed for writing the zip file
CheckExecutable zip
call s:CopyZipFile("evil.zip")
defer delete("X.zip")
e X.zip
:1
let fname = 'pwn'
call search('\V' .. fname)
normal x
call assert_false(filereadable('/etc/ax-pwn'))
let mess = execute(':mess')
call assert_match('Path Traversal Attack', mess)
exe ":normal \<cr>"
:w
call assert_match('zipfile://.*::etc/ax-pwn', @%)
bw
endfunc