Subject: Re: bug#19350: #19350 24.4; Incorrect quoting of %-signs for Windows command shell

From: [email-masked]
Date: Sun, 14 Aug 2016 23:13:43 -0400

Demi Obenour <[email-masked]> writes:

> We don't know what this is being used for. For all we know, someone has written an Emacs plugin that passes a file with an attacker-controlled basename (ex.
> downloaded from the Internet) and uses this function to escape the filename before passing it to an external command, and in a context where there are unbalanced
> double quotes (say) in a known env var. Result: remote execution of arbitrary code.

Hmm, maybe we could fix this by making Emacs refuse to apply environment
variables with names ending in carets?