On Sat, 2018-01-06 at 18:07 -0500, Sandy Napoles Umpierre via samba
wrote:> Hello, can you say me how I can deny in my samba that some aplication can
read my active directory users anonymous.
> ** Alcatel Onetouch Idol 3 (5.5) **
Anonymous access is not enabled in either the Microsoft or Samba AD DC
by default, except to the rootDSE, but it can be turned on with a
dsHuristics flags. Are you seeing anonymous access on your network?
Because this is the second time I've been asked, I did just try, and
this fails for me:
[abartlet at addc samba]$ bin/ldbsearch -H ldap://$SERVER -s sub
search error - LDAP error 1 LDAP_OPERATIONS_ERROR - <00002020:
Operation unavailable without authentication> <>
Thanks,
Andrew Bartlett
> en 06/01/2018 16:55, Andrew Bartlett via samba <samba at
lists.samba.org> escribió:
> >
> > On Sat, 2018-01-06 at 11:11 +0000, Antonios Kalkakos via samba wrote:
> > > I have an AD with two Debian Stretch Samba 4.5.12 DCs. The Samba
and Heimdal Kerberos 7.1.0 packages are installed from Debian repositories.
Management is done from MS-RSAT installed on a Windows 7 Pro client.
> > >
> > > When I select the option "Account is sensitive and cannot be
delegated" (in Active Directory Users and Computers under the Account tab)
for a user account regardless of its privileges, the user cannot logon on any
client PC. Windows 7 responds "Logon failure: user account restriction.
Possible reasons are blank passwords are not allowed, logon hour restrictions,
or a policy restriction has been enforced" and a Debian Stretch client
responds "You are not allowed to logon from this workstation". The
Samba DC will provide a non-forwardable TGT, if you ask for it with kinit -F
command from the Linux client. Issuing the command kinit -f will again fail with
"krb5_get_init_creds: Ticket may not be forwardable".
> > >
> > > Investigation with Wireshark showed that after receiving an
AS-REQ for a TGT with the forwardable flag set, the Samba 4.5.12 DC responds a
KRB5KDC_ERR_POLICY with e-text "Ticket may not be forwardabale" (same
as kinit -f). This behavior is correct according to CVE-2016-2125
(https://www.samba.org/samba/security/CVE-2016-2125.html) which states:
> > >
> > > 0x00100000: UF_NOT_DELEGATED:
> > > The UF_NOT_DELEGATED can be used to disable the ability to get
forwardable TGT
> > > for the account. It means the KDC will respond with an error if
the client asks
> > > for the forwardable ticket. The client typically gives up and
removes the
> > > GSS_C_DELEG_FLAG flag and continues without passing delegated
credentials.
> > > Administrators can use this to disable possible delegation for
the most
> > > privileged accounts (e.g. administrator accounts).
> > >
> > > Upon the initial logon procedure however, both Samba 4.5.12 and
Windows 7 clients will actually give up and not continue asking for a
non-forwardable TGT, which means that the user will be locked out.
> > >
> > > Testing with Wireshark on another AD with one Windows 2008 R2 DC
showed that the DC ignored the forwardable flag on AS-REQ and the user logged in
normally having a non-forwardable TGT. All subsequent TGS requests on the same
logon session from a Windows 7 client didn't have the forwardable flag set.
> > >
> > > Should I fill a bug for that, request to be added on Samba wiki
or am I doing something wrong?
> >
> > Yes, please file a bug. Clearly we need a test for this.
> >
> > (Regarding Rowland's point, the Heimdal package on Debian
won't
> > actually be used by the Samba 4.5 package).
> >
> > Andrew Bartlett
> > --
> > Andrew Bartlett http://samba.org/~abartlet/
> > Authentication Developer, Samba Team http://samba.org
> > Samba Developer, Catalyst IT
http://catalyst.net.nz/services/samba
> >
> >
> > --
> > To unsubscribe from this list go to the following URL and read the
> > instructions: https://lists.samba.org/mailman/options/samba
--
Andrew Bartlett http://samba.org/~abartlet/
Authentication Developer, Samba Team http://samba.org
Samba Developer, Catalyst IT http://catalyst.net.nz/services/samba