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- **********************************************************************
- DDN MGT Bulletin 46 DCA DDN Defense Communications System
- 1 Dec 88 Published by: DDN Network Info Center
- (NIC@SRI-NIC.ARPA) (800) 235-3155
-
-
- DEFENSE DATA NETWORK
-
- MANAGEMENT BULLETIN
-
- The DDN MANAGEMENT BULLETIN is distributed online by the DDN Network
- Information Center under DCA contract as a means of communicating
- official policy, procedures and other information of concern to
- management personnel at DDN facilities. Back issues may be read
- through the TACNEWS server ("@n" command at the TAC) or may be
- obtained by FTP (or Kermit) from the SRI-NIC host [26.0.0.73 or
- 10.0.0.51] using login="anonymous" and password="guest". The pathname
- for bulletins is DDN-NEWS:DDN-MGT-BULLETIN-nn.TXT (where "nn" is the
- bulletin number).
- **********************************************************************
-
- CORRECTION FOR FTP RELATED SECURITY FLAW
-
- Vulnerabilities exist for sites using Berkeley UNIX software or
- software derived from Berkeley UNIX. If you don't know if your
- system uses Berkeley derived UNIX, contact your vendor.
-
- The following direction has been prepared with assistance from
- Berkeley and the Computer Emergency Reaction Team (CERT). The
- fix was independently validated. If you are running FTP service
- (with ftpd) then you will need to take the following steps:
-
- Steps (1), (2), and (3) below should be taken NOW. Follow up
- shortly afterward with the remaining steps.
-
- (1) Become root.
-
- (2) Remove the FTP server program (ftpd). One of the following
- will work. It is OK to do all four.
- rm /etc/ftpd
- rm /usr/etc/ftpd
- rm /etc/in.ftpd
- rm /usr/etc/in.ftpd
-
- (3) EITHER reboot your system OR kill the running ftpd process.
-
- (4) You are safe at this point, but your system is no longer
- providing an FTP server. (You have removed the FTP server
- program from your disk.) NOTE: You will still be able to use
- FTP to obtain the fix from the Network Information Center (NIC),
- but you will not be able to accept externally initiated file
- transfers.
-
- (5) Obtain the ftpd fix from the NIC, from Berkeley, from the
- CERT, or from your vendor. Install according to the instructions.
- NOTE: A version of the patch was disseminated about a month ago
- from Berkeley, and many sites will already have installed the
- fix. The fix that is now being released is a slight improvement
- to this earlier fix, and we suggest making this additional
- upgrade.
-
- The fix is available from the NIC through anonymous FTP. To get
- a copy:
-
- Open an FTP connection to SRI-NIC.ARPA
- Retrieve the contents of NETINFO:UNIX-FTPD.SHAR
-
- (NOTE! If you obtained a copy of the fix prior to receiving this
- bulletin you will need to retrieve a fresh copy of the fix.)
-
- For further information about the retrieval of the patch, call
- the NIC at (800) 235-3155.
-
- The fix is also available from the CERT; send computer mail to:
- CERT [at] SEI.CMU.EDU to get the fix via computer mail.
-
- (6) Once the fix is installed, you can resume providing an FTP
- server. For further information about the patch itself call
- the Computer Emergency Response Team Coordination Center at
- (412) 268-7090, Keith Bostic (Berkeley) at (415) 642-8524, or
- Phil Lapsley or Peter Yee (Berkeley) at (415) 642-7447.
-
- (7) Be sure you have installed the SENDMAIL and FINGERD fixes
- that were previously provided (see DDN Management Bulletin #43).
- It is important that these fixes be installed. The FINGERD hole
- is sufficiently dangerous that you should remove fingerd pending
- installation of the fix. Follow steps (1), (2), and (3) above
- substituting "fingerd" for "ftpd". The fixes for these problems
- are also available from the NIC.
-
- (8) If you are running an (obsolete) BSD 4.2 derived system, then
- it is strongly advised that you obtain an upgrade to 4.3 (or its
- descendants).
-