Re: CVE request(?): gpg: improper file permssions set when en/de-crypting files

[Dan Rosenberg <dan.j.rosenberg () gmail com>]

On 09/21/2012 06:20 AM, Matthias Weckbecker wrote:
> Hello Steve, Kurt, Vitezslav, Tomas, vendors,
>
> we have recently been notified about a potential issue with gpg: When files
> are en/de-crypted the result is written world-readable by default.
> Short example (quote from [1]):
>
>  # de-crypting
>  % gpg sikrit.gpg
>  % ll sikrit*
>    -rw-r--r-- 1 gp users  12 Sep 17 09:41 sikrit
>    -rw------- 1 gp users 480 Sep 17 09:40 sikrit.gpg
>  # en-crypting
>  % echo "my password" > sikrit
>  % chmod go= sikrit
>  % ll sikrit
>    -rw------- 1 gp users 12 Sep 17 09:38 sikrit
>  % gpg -e -r pfeifer sikrit
>  % wipe sikrit
>  % ll sikrit.gpg 
>    -rw-r--r-- 1 gp users 480 Sep 17 09:40 sikrit.gpg
>
> [1] https://bugzilla.novell.com/show_bug.cgi?id=780943
>
> Wouldn't one usually expect files that were previously encrypted to contain
> sensitive content (that's probably why content is encrypted at all)? And if
> so, shouldn't such files be only readable by certain users / group of users
> by default? Otherwise, a file that is e.g. decrypted in /tmp might leak due
> to the file permissions being too loose.

GPG seems to just be honoring the umask:

$ ll secret
-rw------- 1 dan dan 9 Sep 21 06:31 secret
$ umask 0777
$ gpg -e -r dan secret
$ ll secret.gpg
---------- 1 dan dan 605 Sep 21 06:34 secret.gpg

Still might be worth fixing though.

-Dan