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DDN Security Bulletin 04         DCA DDN Defense Communications System
23 Oct 89               Published by: DDN Security Coordination Center
                                     (SCC@NIC.DDN.MIL)  (800) 235-3155
 
                        DEFENSE  DATA  NETWORK
                          SECURITY  BULLETIN
 
The DDN  SECURITY BULLETIN  is distributed  by the  DDN SCC  (Security
Coordination Center) under  DCA contract as  a means of  communicating
information on network and host security exposures, fixes, &  concerns
to security & management personnel at DDN facilities.  Back issues may
be  obtained  via  FTP  (or  Kermit)  from  NIC.DDN.MIL  [26.0.0.73 or
10.0.0.51] using login="anonymous" and password="guest".  The bulletin
pathname is SCC:DDN-SECURITY-nn (where "nn" is the bulletin number).
 
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                     HALLOWEEN PRECAUTIONARY NOTE
 
Halloween is traditionally a time  for tricks of all kinds.   In order
to guard against possible benign or malevolent attempts to affect  the
normal operation of your host,  the DDN SCC staff suggests  taking the
following easy precautions:
 
   1. Write a set of emergency procedures for your site and keep it up
      to date.  Address such things as:
 
         - What would you do if you had an intruder (either a human or
           a computer virus)?
 
         - Who would you  call for help?  HINT:  Read the top  of this
           bulletin!  Also, for 24 hour assistance:
 
           MILNET Trouble Desk -- (A/V) 231-1713 or (800) 451-7413
 
         - Who is in charge of security at your site?
 
         - How would you apply a hardware/software fix if needed?
 
   2. Save your files regularly,  and make file  back-ups often.   Put
      the distribution copies of your  software in  a safe  place away
      from your computer room.  Don't forget where they're stored!
 
   3. Avoid trivial passwords and change them often.   (See the "Green
      Book"  (Department  of  Defense  Password Management Guideline),
      CSC-STD-002-85, for information on the use of passwords.)
 
   4. Check  to  make  sure  your  host  has no  unauthorized users or
      accounts.  Also check for obsolete accounts (a favorite path for
      intruders to gain access).
 
   5. Restrict system  ("superuser", "maint", etc.)  privileges to the
      minimum number of accounts you possibly can.
 
   6. Well publicized accounts including "root", "guest", etc. AND the
      personal account  for the  system administrator  should NOT have
      system privileges.   (Past experience  has shown  that these IDs
      are more susceptible to successful intruder attacks.)
 
   7. Keep your maintenance contracts active.
 
Of course,  these steps should be taken throughout the year as part of
your regular operating procedure.
 
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