WorldView Wnn vulnerability

[SGI Security Coordinator <agent99 () CSD SGI COM>]

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______________________________________________________________________________
                           SGI Security Advisory

         Title:  WorldView Wnn vulnerability
        Number:  20000803-01-A
          Date:  August 17, 2000
______________________________________________________________________________

SGI provides this information freely to the SGI user community for its
consideration, interpretation, implementation and use.   SGI recommends
that this information be acted upon as soon as possible.

SGI provides the information in this Security Advisory on an "AS-IS" basis
only, and disclaims all warranties with respect thereto, express, implied
or otherwise, including, without limitation, any warranty of merchantability
or fitness for a particular purpose.  In no event shall SGI be liable for
any loss of profits, loss of business, loss of data or for any indirect,
special, exemplary, incidental or consequential damages of any kind arising
from your use of, failure to use or improper use of any of the instructions
or information in this Security Advisory.
______________________________________________________________________________


SGI acknowledges the root buffer overflow vulnerability in WorldView reported
by Shadow Penguin Security Org. on the FreeWnn Mailing List:
http://www.tomo.gr.jp/users/wnn/0008ml/msg00000.html (in Japanese)
and also reported by Omron Software on
http://www.omronsoft.co.jp/SP/support/pcunix/wnn/update1.html (in Japanese)

SGI is currently working on patches.

Omron WorldView is an optional purchased product used by SGI customers that
require foreign language support in IRIX. It is not installed by default
on base IRIX. Only SGI systems that have WorldView installed are
vulnerable to this issue.

The WorldView vulnerability can lead to root access through a buffer
overflow exploit. A workaround is provided below to minimize exposure
to the buffer overflow by changing ownership of the jserver to a
non-privileged user.

No further information is available at this time.

As further information becomes available, additional advisories will be
issued via the normal SGI security information distribution methods
including the wiretap mailing list.

The steps below can be used to minimize exposure to the WorldView
vulnerability. (Translated from Japanese)


     1) Become the root user on the system.

              % /bin/su -
              Password:
              #

     2) Verify WorldView is installed. Only systems that have WorldView
        installed are vulnerable.

              # versions -b

     I  WorldView_base_jp    05/06/1998  WorldView Base Japanese 6.5
     I  WorldView_books_jp   05/06/1998  WorldView Books: Japanese 6.5
     I  WorldView_fonts_jp1  05/06/1998  WorldView Fonts Japanese, 6.5
     I  WorldView_japanese   05/06/1998  WorldView Japanese 6.5

    3) If the WorldView is not currently needed, disable the jserver.

              # chkconfig jserver off

       Note: This will disable Japanese character input support.

    4) Add the following lines to the files /etc/password and /etc/group
       with a text editor like vi.

       /etc/passwd:

                wnn:*:127:127:Wnn System Account:/usr/lib/wnn6:/bin/sh

       /etc/group:

                wnn:*:127

    5) Change the owner of the WNN related files.

              # chown -R wnn.sys /usr/bin/Wnn6
              # chown -R wnn.sys /usr/lib/wnn6

    6) Verify that the file ownership changes have been made.

              # ls -ls /usr/bin/Wnn6/jserver
              1136 -r-sr-xr-x    1 wnn      sys       578660

              # ls -ls /usr/lib/wnn6/serverdefs
              8 -rw-r--r--    1 wnn      sys          662

     7) Reboot the system.

              # reboot


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______________________________________________________________________________
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