Re: emacs-29 3c1693d08b0: Fix Elisp code injection vulnerability in emacsclient-mail.desktop

[Po Lu <luangruo@yahoo.com>]

Ulrich Müller <ulm@gentoo.org> writes:

>  Categories=Network;Email;
>  Comment=GNU Emacs is an extensible, customizable text editor - and more
> -Exec=sh -c "exec emacsclient --alternate-editor= --display=\\"\\$DISPLAY\\" --eval \\"(message-mailto \\\\\\"\\$1\\\\\\")\\"" sh %u
> +# We want to pass the following commands to the shell wrapper:
> +# u=${1//\\/\\\\}; u=${u//\"/\\\"}; exec emacsclient --alternate-editor= --display="$DISPLAY" --eval "(message-mailto \"$u\")"
> +# Special chars '"', '$', and '\' must be escaped as '\\"', '\\$', and '\\\\'.
> +Exec=bash -c "u=\\${1//\\\\\\\\/\\\\\\\\\\\\\\\\}; u=\\${u//\\\\\\"/\\\\\\\\\\\\\\"}; exec emacsclient --alternate-editor= --display=\\"\\$DISPLAY\\" --eval \\"(message-mailto \\\\\\"\\$u\\\\\\")\\"" bash %u
>  Icon=emacs
>  Name=Emacs (Mail, Client)
>  MimeType=x-scheme-handler/mailto;
> @@ -13,7 +16,7 @@ Actions=new-window;new-instance;
>  
>  [Desktop Action new-window]
>  Name=New Window
> -Exec=sh -c "exec emacsclient --alternate-editor= --create-frame --eval \\"(message-mailto \\\\\\"\\$1\\\\\\")\\"" sh %u
> +Exec=bash -c "u=\\${1//\\\\\\\\/\\\\\\\\\\\\\\\\}; u=\\${u//\\\\\\"/\\\\\\\\\\\\\\"}; exec emacsclient --alternate-editor= --create-frame --eval \\"(message-mailto \\\\\\"\\$u\\\\\\")\\"" bash %u
>  
>  [Desktop Action new-instance]
>  Name=New Instance

What if the system in question has no bash?  This is not a theoretical
question, because I have access to one system which does have .desktop
files, but only csh, /bin/sh (which is useless), and ksh93.