vim-patch:9.2.0663: [security]: runtime(netrw): code injection in local file deletion

Problem:  [security]: s:NetrwLocalRmFile() escapes only the backslash in
          the file name before passing it to :execute, so a name
          containing "|" injects arbitrary Ex commands when the file is
          deleted (cipher-creator)
Solution: Use fnameescape() to correctly escape the file name
          (Yasuhiro Matsumoto).

Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-vhh8-v6wx-hjjh

Supported by AI

55bc757a5d

Co-authored-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>

runtime/pack/dist/opt/netrw/autoload/netrw.vim

@@ -1,7 +1,7 @@
 " Creator:    Charles E Campbell
 " Previous Maintainer: Luca Saccarola <github.e41mv@aleeas.com>
 " Maintainer: This runtime file is looking for a new maintainer.
-" Last Change: 2026 Jun 10
+" Last Change: 2026 Jun 16
 " Copyright:  Copyright (C) 2016 Charles E. Campbell {{{1
 "             Permission is hereby granted to use and distribute this code,
 "             with or without modifications, provided that this copyright
@@ -3083,7 +3083,7 @@ function s:NetrwBrowse(islocal,dirname)
     elseif !a:islocal && dirname !~ '[\/]$' && dirname !~ '^"'
         " s:NetrwBrowse :  remote regular file handler {{{3
         if bufname(dirname) != ""
-            exe "NetrwKeepj b ".bufname(dirname)
+            exe "NetrwKeepj b ".fnameescape(bufname(dirname))
         else
             " attempt transfer of remote regular file
 
@@ -8804,7 +8804,7 @@ function s:NetrwLocalRmFile(path, fname, all)
             call netrw#msg#Notify('ERROR', printf("unable to delete <%s>!", rmfile))
         else
             " Remove file only if there are no pending changes
-            execute printf('silent! bwipeout %s', rmfile)
+            execute printf('silent! bwipeout %s', fnameescape(rmfile))
         endif
 
     elseif dir && (all || empty(ok))

test/old/testdir/test_plugin_netrw.vim

@@ -856,4 +856,24 @@ func Test_netrw_injection()
   endtry
 endfunc
 
+" Deleting a file whose name contains an Ex command separator must not let the
+" name inject commands into the :execute in s:NetrwLocalRmFile().
+func Test_netrw_local_rm_injection()
+  CheckUnix
+  let dir   = getcwd() . '/Xnetrwrm'
+  let fname = "x|let g:injected = 1"
+  call mkdir(dir, 'pR')
+  call writefile([], dir . '/' . fname)
+  try
+    call netrw#Call('NetrwLocalRmFile', dir, fname, 1)
+    call assert_false(exists('g:injected'), 'filename must not inject Ex commands')
+    " The file is removed before the sink, so its absence also confirms the
+    " vulnerable code path was actually exercised (not skipped on an error).
+    call assert_false(filereadable(dir . '/' . fname), 'crafted file must be deleted')
+  finally
+    call delete(dir . '/' . fname)
+    unlet! g:injected
+  endtry
+endfunc
+
 " vim:ts=8 sts=2 sw=2 et