patch 9.1.1164: [security]: code execution with tar.vim and special crafted tar files
Problem: editing a special crafted tar file allows code execution
(RyotaK, after 129a8446d23cd9cb4445fcfea259cba5e0487d29)
Solution: escape the filename before feeding it to the `:read` command
Github Advisory:
https://github.com/vim/vim/security/advisories/GHSA-wfmf-8626-q3r3
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/autoload/tar.vim b/runtime/autoload/tar.vim
index 1c2ed78..14e68b7 100644
--- a/runtime/autoload/tar.vim
+++ b/runtime/autoload/tar.vim
@@ -11,6 +11,7 @@
" 2025 Feb 06 by Vim Project: add support for lz4 (#16591)
" 2025 Feb 28 by Vim Project: add support for bzip3 (#16755)
" 2025 Mar 01 by Vim Project: fix syntax error in tar#Read()
+" 2025 Mar 02 by Vim Project: escape the filename before using :read
"
" Contains many ideas from Michael Toren's <tar.vim>
"
@@ -284,6 +285,8 @@
set report=10
let tarfile = substitute(a:fname,'tarfile:\(.\{-}\)::.*$','\1','')
let fname = substitute(a:fname,'tarfile:.\{-}::\(.*\)$','\1','')
+ " be careful not to execute special crafted files
+ let escape_file = fname->fnameescape()
" changing the directory to the temporary earlier to allow tar to extract the file with permissions intact
if !exists("*mkdir")
@@ -361,13 +364,13 @@
if tarfile =~# '\.bz2$'
exe "sil! r! bzip2 -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\.bz3$'
exe "sil! r! bzip3 -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\.\(gz\)$'
exe "sil! r! gzip -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\(\.tgz\|\.tbz\|\.txz\)'
if has("unix") && executable("file")
let filekind= system("file ".shellescape(tarfile,1))
@@ -376,40 +379,40 @@
endif
if filekind =~ "bzip2"
exe "sil! r! bzip2 -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif filekind =~ "bzip3"
exe "sil! r! bzip3 -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif filekind =~ "XZ"
exe "sil! r! xz -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif filekind =~ "Zstandard"
exe "sil! r! zstd --decompress --stdout -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
else
exe "sil! r! gzip -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
endif
elseif tarfile =~# '\.lrp$'
exe "sil! r! cat -- ".shellescape(tarfile,1)." | gzip -d -c - | ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\.lzma$'
exe "sil! r! lzma -d -c -- ".shellescape(tarfile,1)."| ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\.\(xz\|txz\)$'
exe "sil! r! xz --decompress --stdout -- ".shellescape(tarfile,1)." | ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
elseif tarfile =~# '\.\(lz4\|tlz4\)$'
exe "sil! r! lz4 --decompress --stdout -- ".shellescape(tarfile,1)." | ".g:tar_cmd." -".g:tar_readoptions." - ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
else
if tarfile =~ '^\s*-'
" A file name starting with a dash is taken as an option. Prepend ./ to avoid that.
let tarfile = substitute(tarfile, '-', './-', '')
endif
exe "silent r! ".g:tar_cmd." -".g:tar_readoptions.shellescape(tarfile,1)." ".tar_secure.shellescape(fname,1).decmp
- exe "read ".fname
+ exe "read ".escape_file
endif
redraw!