samba announce - Jan 2022 - [Announce] Samba 4.13.16 Security Release is available for Download

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

This is a security release in order to address the following defects:

o CVE-2021-43566:? mkdir race condition allows share escape in Samba 4.x.
https://www.samba.org/samba/security/CVE-2021-43566.html


======Details
======
o? CVE-2021-43566:
 ?? All versions of Samba prior to 4.13.16 are vulnerable to a malicious
 ?? client using an SMB1 or NFS symlink race to allow a directory to be
 ?? created in an area of the server file system not exported under the
 ?? share definition. Note that SMB1 has to be enabled, or the share
 ?? also available via NFS in order for this attack to succeed.

 ?? Clients that have write access to the exported part of the file system
 ?? under a share via SMB1 unix extensions or NFS can create symlinks that
 ?? can race the server by renaming an existing path and then replacing it
 ?? with a symlink. If the client wins the race it can cause the server to
 ?? create a directory under the new symlink target after the exported
 ?? share path check has been done. This new symlink target can point to
 ?? anywhere on the server file system. The authenticated user must have
 ?? permissions to create a directory under the target directory of the
 ?? symlink.

 ?? This is a difficult race to win, but theoretically possible. Note that
 ?? the proof of concept code supplied wins the race only when the server
 ?? is slowed down and put under heavy load. Exploitation of this bug has
 ?? not been seen in the wild.


Changes since 4.13.15
---------------------

o? Jeremy Allison <jra at samba.org>
 ?? * BUG 13979: CVE-2021-43566: mkdir race condition allows share 
escape in Samba 4.x


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

Please discuss this release on the samba-technical mailing list or by
joining the #samba-technical IRC channel on irc.libera.chat or the
#samba-technical:matrix.org matrix channel.

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 AA99442FB680B620).? 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-4.13.16.html

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

 ??????????????????????? --Enjoy
 ??????????????????????? The Samba Team