samba - Oct 2020 - [Announce] Samba 4.13.1, 4.12.9 and 4.11.15 Security Releases Available

Release Announcements
---------------------

These are a security releases in order to address the following defects:

o CVE-2020-14318: Missing handle permissions check in SMB1/2/3 ChangeNotify.
o CVE-2020-14323: Unprivileged user can crash winbind.
o CVE-2020-14383: An authenticated user can crash the DCE/RPC DNS with easily
		  crafted records.


======Details
======
o  CVE-2020-14318:
   The SMB1/2/3 protocols have a concept of "ChangeNotify", where a
client can
   request file name notification on a directory handle when a condition such as
   "new file creation" or "file size change" or "file
timestamp update" occurs.

   A missing permissions check on a directory handle requesting ChangeNotify
   meant that a client with a directory handle open only for
   FILE_READ_ATTRIBUTES (minimal access rights) could be used to obtain change
   notify replies from the server. These replies contain information that should
   not be available to directory handles open for FILE_READ_ATTRIBUTE only.

o  CVE-2020-14323:
   winbind in version 3.6 and later implements a request to translate multiple
   Windows SIDs into names in one request. This was done for performance
   reasons: Active Directory domain controllers can do multiple SID to name
   translations in one RPC call. It was an obvious extension to also offer this
   batch operation on the winbind unix domain stream socket that is available to
   local processes on the Samba server to reduce network round-trips to the
   domain controller.

   Due to improper input validation a hand-crafted packet can make winbind
   perform a NULL pointer dereference and thus crash.

o  CVE-2020-14383:
   Some DNS records (such as MX and NS records) usually contain data in the
   additional section. Samba's dnsserver RPC pipe (which is an
administrative
   interface not used in the DNS server itself) made an error in handling the
   case where there are no records present: instead of noticing the lack of
   records, it dereferenced uninitialised memory, causing the RPC server to
   crash. This RPC server, which also serves protocols other than dnsserver,
   will be restarted after a short delay, but it is easy for an authenticated
   non-admin attacker to crash it again as soon as it returns. The Samba DNS
   server itself will continue to operate, but many RPC services will not.

For more details, please refer to the security advisories.


Changes:
--------

o  Jeremy Allison <jra at samba.org>
   * BUG 14434: CVE-2020-14318: s3: smbd: Ensure change notifies can't get
set
     unless the directory handle is open for SEC_DIR_LIST.

o  Douglas Bagnall <douglas.bagnall at catalyst.net.nz>
   * BUG 12795: CVE-2020-14383: Remote crash after adding NS or MX records using
     'samba-tool'.
   * BUG 14472: CVE-2020-14383: Remote crash after adding MX records.

o  Volker Lendecke <vl at samba.org>
   * BUG 14436: CVE-2020-14323: winbind: Fix invalid lookupsids DoS.


#######################################
Reporting bugs & Development Discussion
#######################################

Please discuss this release on the samba-technical mailing list or by
joining the #samba-technical IRC channel on irc.freenode.net.

If you do report problems then please try to send high quality
feedback. If you don't provide vital information to help us track down
the problem then you will probably be ignored.  All bug reports should
be filed under the Samba 4.1 and newer product in the project's Bugzilla
database (https://bugzilla.samba.org/).


======================================================================= Our
Code, Our Bugs, Our Responsibility.
== The Samba Team
=====================================================================


===============Download Details
===============
The uncompressed tarballs and patch files have been signed
using GnuPG (ID 6F33915B6568B7EA).  The source code can be downloaded
from:

        https://download.samba.org/pub/samba/stable/

The release notes are available online at:

        https://www.samba.org/samba/history/samba-4.13.1.html
        https://www.samba.org/samba/history/samba-4.12.9.html
        https://www.samba.org/samba/history/samba-4.11.15.html

Our Code, Our Bugs, Our Responsibility.
(https://bugzilla.samba.org/)

                        --Enjoy
                        The Samba Team
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