Document ID:  HPSBMP0107-012
Date Loaded:  20010702
      Title:  Security Vulnerability in CIFS/9000 Server #2

------------------------------------------------------------------------
    HEWLETT-PACKARD COMPANY SECURITY ADVISORY: #0012, 3 July '01
------------------------------------------------------------------------

The information in the following Security Advisory should be acted upon
as soon as possible.  Hewlett-Packard Company will not be liable for any
consequences to any customer resulting from customer's failure to fully
implement instructions in this Security Advisory as soon as possible.

------------------------------------------------------------------------

PROBLEM:  CIFS/3000 Server (Samba) - use of certain configuration
          options may compromise system security

PLATFORM: All HP3000 MPE/iX servers running Samba/iX

DAMAGE:   Data may be appended to arbitrary files and devices

SOLUTION: Remove offending configuration options to avoid vulnerability

------------------------------------------------------------------------
A. Background

   The NetBIOS name of remote clients is substituted into the "%m"  macro
   wherever it occurs in the configuration file smb.conf. The use of
   contrived NetBIOS names may result in Samba using a file path
   outside of the intended Samba directories.  This can be used to
   cause Samba to append data to important system files, which in
   turn can be used to compromise security on the server.

B. Fixing the problem

   An immediate fix is to edit your smb.conf configuration file and
   remove all occurances of the macro "%m".  Depending on the
   requirements of each site, other smb.conf macros may be suitable
   replacements.

C. Workarounds

   The "log file" option is the most vulnerable to this redefinition
   problem.  The sample configuration file supplied with CIFS/3000
   Server contains the path "/var/opt/samba/log.%m" for this option.
   Using this default path does NOT create a vulnerability unless
   there happens to exist a subdirectory in /var/opt/samba which
   starts with the prefix "log.".

   Sites that chooose to maintain the use of the "%m" macro in the
   "log file" option should use the default value:
      /var/opt/samba/log.%m


D. To subscribe to automatically receive future NEW HP Security
   Bulletins from the HP IT Resource Center via electronic mail,
   do the following:

   Use your browser to get to the HP IT Resource Center page
   at:

      http://itrc.hp.com

   Under the Maintenance and Support Menu:
   click on the "more..." link.  Then -

   Use the 'Login' tab at the left side of the screen to login
   using your ID and password.  Check with your system
   administrator to see if you have an existing login or use
   the "Register" button at the left to create a login.  You
   will need to login in order to gain access to many areas of
   the ITRC. Remember to save the User ID assigned to you, and
   your password.

   Under the "Notifications" section (near the bottom of
   the page), select "Support Information Digests".

   To -subscribe- to future HP Security Bulletins or other
   Technical Digests, click the check box (in the left column)
   for the appropriate digest and then click the "Update
   Subscriptions" button at the bottom of the page.

    or

   To -review- bulletins already released, select the link
   (in the middle column) for the appropriate digest.

   To -gain access- to the Security Patch Matrix, select
   the link for "The Security Bulletins Archive".  (near the
   bottom of the page)  Once in the archive the third link is
   to the current Security Patch Matrix. Updated daily, this
   matrix categorizes security patches by platform/OS release,
   and by bulletin topic.  Security Patch Check completely
   automates the process of reviewing the patch matrix for
   HP-UX 11.XX systems.

   For information on the HP-UX Security Patch Check tool, see:
    http://www.software.hp.com/cgi-bin/swdepot_parser.cgi/cgi/
           displayProductInfo.pl?productNumber3DB6834AA"

   The security patch matrix is also available via anonymous ftp:

   ftp.itrc.hp.com:~ftp/export/patches/hp-ux_patch_matrix

   On the "Support Information Digest Main" page:
   click on the "HP Security Bulletin Archive".


E. To report new security vulnerabilities, send email to

     [log in to unmask]

    Please encrypt any exploit information using the security-alert
    PGP key, available from your local key server, or by sending a
    message with a -subject- (not body) of 'get key' (no quotes) to
    [log in to unmask]

    Permission is granted for copying and circulating this Advisory
    to Hewlett-Packard (HP) customers (or the Internet community) for
    the purpose of alerting them to problems, if and only if, the
    Advisory is not edited or changed in any way, is attributed to
    HP, and provided such reproduction and/or distribution is
    performed for non-commercial purposes.

    Any other use of this information is prohibited. HP is not liable
    for any misuse of this information by any third party.
______________________________________________________________________
-----End of Document ID:  HPSBMP0107-012--------------------------------------
--
Ted Ashton ([log in to unmask]), Info Sys, Southern Adventist University
          ==========================================================
Epitaph on Newton:
Nature and Nature's law lay hid in night:
God said, "Let Newton be!," and all was light.
[added by Sir John Collings Squire:
It did not last: the Devil shouting "Ho.
Let Einstein be," restored the status quo]
                        -- Pope, Alexander (1688-1744)
          ==========================================================
         Deep thoughts to be found at http://www.southern.edu/~ashted

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *