Emacs message-mode uses certain text strings to indicate how to attach files to outgoing mail. If these are present in the text of an email, and a user is tricked into replying to the message, the user’s files could be exposed. --- To demonstrate this, open a reply to this message then remove the exclamation marks after the hash marks below. Create a file in your home directory called passwd. Then press C-u M-x mml-preview. A (possibly base64-encoded) version of your ~/passwd file will replace the following lines: <#!part type="application/octet-stream" filename="~/passwd" disposition=attachment description=foo> <#!/part> It works equally well (and more dangerously) with /etc/passwd, but I didn't use that filename here to avoid the danger of someone accidentally attaching their /etc/passwd to a reply in this thread! emacs/notmuch-mua.el | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/emacs/notmuch-mua.el b/emacs/notmuch-mua.el index d8ab822..c25c6b9 100644 --- a/emacs/notmuch-mua.el +++ b/emacs/notmuch-mua.el @@ -115,7 +115,8 @@ list." (push-mark)) (set-buffer-modified-p nil) - (message-goto-body)) + (message-goto-body) + (mml-quote-region (point) (mark))) (defun notmuch-mua-forward-message () (message-forward) -- 1.7.8.3