****************************************
                            * IMPORTANT: Security bugfix for Samba *
                            ****************************************

       This release provides an important security fix outlined in the
       release notes that follow. This is the latest stable release of
       Samba and the version that all production Samba servers should be
       running for all current bug-fixes.

       The source code can be downloaded from :

           http://download.samba.org/samba/ftp/

       in the file samba-2.2.8.tar.gz or samba-2.2.8.tar.bz2.
       Both archives have been signed using the Samba Distribution Key.

       Binary packages will be released shortly for major platforms and
       can be found at

           http://download.samba.org/samba/ftp/Binary_Packages/

       As always, all bugs are our responsibility.

                                  --Sincerely
                                  The Samba Team

       Summary
       -------

       The SuSE security audit team, in particular Sebastian
       Krahmer, has found a flaw in the Samba main smbd code which
       could allow an external attacker to remotely and anonymously gain
       Super User (root) privileges on a server running a Samba server.

       This flaw exists in previous versions of Samba from 2.0.x to 2.2.7a
       inclusive.  This is a serious problem and all sites should either
       upgrade to Samba 2.2.8 immediately or prohibit access to TCP ports 139
       and 445. Advice created by Andrew Tridgell, the leader of the Samba Team,
       on how to protect an unpatched Samba server is given at the end of this
       section.

       The SMB/CIFS protocol implemented by Samba is vulnerable to many
       attacks, even without specific security holes.  The TCP ports 139 and
       the new port 445 (used by Win2k and the Samba 3.0 alpha code in
       particular) should never be exposed to untrusted networks.

       Description
       -----------

       A buffer overrun condition exists in the SMB/CIFS packet fragment
       re-assembly code in smbd which would allow an attacker to cause smbd
       to overwrite arbitrary areas of memory in its own process address
       space. This could allow a skilled attacker to inject binary specific
       exploit code into smbd.

       This version of Samba adds explicit overrun and overflow checks on
       fragment re-assembly of SMB/CIFS packets to ensure that only valid
       re-assembly is performed by smbd.

       In addition, the same checks have been added to the re-assembly
       functions in the client code, making it safe for use in other
       services.

       Credit
       ------

       This security flaw was discovered and reported to the Samba Team by
       Sebastian Krahmer  of the SuSE Security Audit Team.
       The fix was prepared by Jeremy Allison and reviewed by engineers from
       the Samba Team, SuSE, HP, SGI, Apple, and the Linux vendor engineers
       on the Linux Vendor security mailing list.

       The Samba Team would like to thank SuSE and Sebastian Krahmer for
       their excellent auditing work and for drawing attention to this flaw.

       Patch Availability
       -----------------

       As this is a security issue, patches for this flaw specific to earlier
       versions of Samba will be posted on the samba-technical@samba.org
       mailing list as requested.

       ************************************
       Protecting an unpatched Samba server
       ************************************

         Samba Team, March 2003

         This is a note on how to provide your Samba server some
         protection against the recently discovered remote security
         hole if you are unable to upgrade to the fixed version
         immediately. Even if you do upgrade you might like to think
         about the suggestions in this note to provide you with
         additional levels of protection.

         Using host based protection
         ---------------------------

         In many installations of Samba the greatest threat comes for
         outside your immediate network. By default Samba will accept
         connections from any host, which means that if you run an
         insecure version of Samba on a host that is directly
         connected to the Internet you can be especially vulnerable.

         One of the simplest fixes in this case is to use the 'hosts
         allow' and 'hosts deny' options in the Samba smb.conf
         configuration file to only allow access to your server from a
         specific range of hosts. An example might be:

           hosts allow = 127.0.0.1 192.168.2.0/24 192.168.3.0/24
           hosts deny = 0.0.0.0/0

         The above will only allow SMB connections from 'localhost'
         (your own computer) and from the two private networks
         192.168.2 and 192.168.3. All other connections will be
         refused connections as soon as the client sends its first
         packet. The refusal will be marked as a 'not listening on
         called name' error.

         Using interface protection
         --------------------------

         By default Samba will accept connections on any network
         interface that it finds on your system. That means if you
         have a ISDN line or a PPP connection to the Internet then
         Samba will accept connections on those links. This may not be
         what you want.

         You can change this behavior using options like the
         following:

           interfaces = eth* lo
           bind interfaces only = yes

         that tells Samba to only listen for connections on interfaces
         with a name starting with 'eth' such as eth0, eth1, plus on
         the loopback interface called 'lo'. The name you will need to
         use depends on what OS you are using. In the above I used the
         common name for ethernet adapters on Linux.

         If you use the above and someone tries to make a SMB
         connection to your host over a PPP interface called 'ppp0',
         they will get a TCP connection refused reply. In that
         case no Samba code is run at all as the operating system has
         been told not to pass connections from that interface to any
         process.

         Using a firewall
         ----------------

         Many people use a firewall to deny access to services that
         they don't want exposed outside their network. This can be a
         very good idea, although I would recommend using it in
         conjunction with the above methods so that you are protected
         even if your firewall is not active for some reason.

         If you are setting up a firewall then you need to know what
         TCP and UDP ports to allow and block. Samba uses the
         following:

           UDP/137    - used by nmbd
           UDP/138    - used by nmbd
           TCP/139    - used by smbd
           TCP/445    - used by smbd

         The last one is important as many older firewall setups may
         not be aware of it, given that this port was only added to
         the protocol in recent years.

         Using a IPC$ share deny
         -----------------------

         If the above methods are not suitable, then you could also
         place a more specific deny on the IPC$ share that is used in
         the recently discovered security hole. This allows you to
         offer access to other shares while denying access to IPC$
         from potentially untrustworthy hosts.

         To do that you could use:

           [ipc$]
               hosts allow = 192.168.115.0/24 127.0.0.1
               hosts deny = 0.0.0.0/0

         this would tell Samba that IPC$ connections are not allowed
         from anywhere but the two listed places (localhost and a
         local subnet). Connections to other shares would still be
         allowed. As the IPC$ share is the only share that is always
         accessible anonymously this provides some level of protection
         against attackers that do not know a username/password for
         your host.

         If you use this method then clients will be given a 'access
         denied' reply when they try to access the IPC$ share. That
         means that those clients will not be able to browse shares,
         and may also be unable to access some other resources.

         I don't recommend this method unless you cannot use one of
         the other methods listed above for some reason.

         Upgrading Samba
         ---------------

         Of course the best solution is to upgrade Samba to a version
         where the bug has been fixed. If you wish to also use one of
         the additional measures above then that would certainly be a
         good idea.

         Please check regularly on http://www.samba.org/ for updates
         and important announcements.