Commit: runtime(zip): Detect path traversal issues on Windows

[Christian Brabandt]

runtime(zip): Detect path traversal issues on Windows

Commit: https://github.com/vim/vim/commit/6836599733950e1f52864a9742ff3e5bca5820fd
Author: Christian Brabandt <c...@256bit.org>
Date: Tue Apr 14 14:42:48 2026 +0200

runtime(zip): Detect path traversal issues on Windows

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

diff --git a/runtime/autoload/zip.vim b/runtime/autoload/zip.vim
index f4482fd7f..6a2d6daa3 100644
--- a/runtime/autoload/zip.vim
+++ b/runtime/autoload/zip.vim
@@ -22,6 +22,7 @@
" 2026 Mar 08 by Vim Project: Make ZipUpdatePS() check for powershell
" 2026 Apr 01 by Vim Project: Detect more path traversal attacks
" 2026 Apr 05 by Vim Project: Detect more path traversal attacks
+" 2026 Apr 14 by Vim Project: Detect more path traversal attacks on Windows
" 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,
@@ -405,7 +406,12 @@ fun! zip#Write(fname)
else
let zipfile = substitute(a:fname,'^.\{-}zipfile://\(.\{-}\)::[^\].*$',' ','')
let fname = substitute(a:fname,'^.\{-}zipfile://.\{-}::\([^\].*\)$',' ','')
- " TODO: what to check on MS-Windows to avoid writing absolute paths?
+ " fname should not start with drive leter or a UNC path
+ if fname =~ '^\%(\%( :[\/]\)\|[\/]\{2}\)'
+ call s:Mess('Error', "***error*** (zip#Write) Path Traversal Attack detected, not writing!")
+ call s:ChgDir(curdir,s:WARNING,"(zip#Write) unable to return to ".curdir."!")
+ return
+ endif
endif
if fname =~ '^[.]\{1,2}/'
let gnu_cmd = g:zip_zipcmd . ' -d ' . s:Escape(fnamemodify(zipfile,":p"),0) . ' ' . s:Escape(fname,0)