Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Thu, 26 Sep 2013 11:11:59 +1000
From: Michael Samuel <mik@...net.net>
To: oss-security@...ts.openwall.com
Subject: RESEND: CVE Request: pwgen

Hi,

No CVEs have been assigned for this, and as far as I can tell no
distributions have patched.

On 6 June 2013 14:19, Michael Samuel <mik@...net.net> wrote:

> I've done some further analysis of the program after reading the previous
> thread, and I think there needs to be CVEs and fixes for:
>
> - When used from a non-tty passwords are trivially weak by default (first
> reported by Solar Designer)
> - Phonemes mode has heavy bias and is enabled by default (first reported
> by Solar Designer)
> - Silent fallback to insecure entropy (first reported by Jean-Michel
> Vourgère) (Debian bug #672241 - tagged as "wishlist")
> - Secure mode has bias towards numbers and uppercase letters
>
> I've attached a patch that fixes most issues - it doesn't solve the bias
> towards numbers, because it's caused by requiring at-least one number per
> password - so in an 8 character password there'd have to be 0.1 numbers to
> avoid bias.  There's an argument to be made for removing the at-least-one
> rule, but if the system that password is being used with has those rules,
> it doesn't fix the problem anyway.  Perhaps a separate flag for that?
>
> The changes are:
>
> - Print a message and abort() of there's trouble opening or reading
> /dev/urandom (So apport should pick up any packages that have been using
> insecure entropy)
> - Make "-s" the default
> - Add an argument --insecure-phonemes (or -P)
> - Non-tty passwords are now as secure as tty
> - Require lower-case characters be present to even out some bias
> - Pull in passwdqc as a Suggests on the debian package - pwqgen can
> generate sane random passphrases
>
> I can't imagine any reasonable use-case for the non-tty defaults (except
> maybe combining with espeak as an enhanced interrogation technique), and
> you can be certain that there's some people out there with it embedded in a
> script that's generating useless passwords.
>
> For phonemes mode in general, the bias is extreme, there are a limited
> number of possible combinations and it is generally not suitable for
> security purposes.  I have some fairly detailed analysis of it, but I
> believe this list has a no-exploits policy...
>
> Regards,
>   Michael
>

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.