Re: CVE request: samba pam_winbind authentication fails open

[Kurt Seifried <kseifried () redhat com>]

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On 12/02/2013 02:24 PM, Vincent Danen wrote:
> Just cutting-and-pasting from the bug I just filed.  The following
> was reported to us, but had been reported upstream last year.
>
> It was reported [1] that Samba's pam_winbind module would fail
> open (allowing access) when the require_membership_of option is
> used as an argument to pam_winbind, and contains a non-existent
> group as the value.  In such a configuration, rather then failing
> and not permitting authentication which is what would be expected,
> pam_winbind will allow authentication to proceed.
>
> For instance, if the following is specified and the user is not a
> member of the group 'Admin', they will not obtain access to the
> system:
>
> auth        sufficient    pam_winbind.so use_first_pass 
> require_membership_of=Admin
>
> On the other hand, if the non-existent group 'AdminOops' is
> specified, the user is obviously not a member of said group,
> authentication will be permitted:
>
> auth        sufficient    pam_winbind.so use_first_pass 
> require_membership_of=AdminOops
>
> The commit [2] that most likely introduced this flaw indicates that
> this was introduced October 2009 and another commit [3] looks like
> the fix, although that is for another bug [4] that's somewhat
> related to this issue and somewhat not.
>
> [1]
> https://lists.samba.org/archive/samba-technical/2012-June/084593.html
[2]
> http://git.samba.org/?p=samba.git;a=commit;h=31f1a36901b5b8959dc51401c09c114829b50392
>
>  [3] 
> http://git.samba.org/?p=samba.git;a=commitdiff;h=f62683956a3b182f6a61cc7a2b4ada2e74cde243
>
>  [4] https://bugzilla.samba.org/show_bug.cgi?id=8598
>
>
> Could a CVE be assigned to this issue?

Please use CVE-2012-6150 for this issue.

- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
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