Operating System:


09 April 2001

Protect yourself against future threats.


             AUSCERT External Security Bulletin Redistribution

       ESB-2001.140 -- HP Support Information Digest HPSBUX0104-148
                      Sec. Vulnerability in xntpd(1M)
                               10 April 2001


        AusCERT Security Bulletin Summary

Product:                ntp
Vendor:                 Hewlett-Packard
Operating System:       HP-UX 10.XX
                        HP-UX 11.XX
Platform:               HP9000 Series 700
                        HP9000 Series 800
Impact:                 Denial of Service
                        Increased Privileges
Access Required:        Remote

Ref:                    ESB-2001.138

- --------------------------BEGIN INCLUDED TEXT--------------------

Document ID:  HPSBUX0104-148
Date Loaded:  20010407
      Title:  Sec. Vulnerability in xntpd(1M)

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

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.

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PROBLEM:  The HP-UX NTP daemon contains an exploitable vulnerability.

PLATFORM: HP9000 Series 700/800 running HP-UX releases 10.XX and 11.XX.

DAMAGE:   Possible denial of service, increase of priviledge.

SOLUTION: Install the workaround configuration detailed below.

AVAILABILITY: Patches are currently being developed, whereupon this
              advisory will be upgraded to a bulletin.
- -------------------------------------------------------------------------
   A. Background
      A buffer overflow has been discovered on various Unix-derived
      operating systems in its NTP daemon.  Hewlett-Packard Company
      ships xntpd on HP-UX releases and has determined that it too,
      is vulnerable.

   B. Recommended solution
      Hewlett-Packard Company recommends that xntpd be shut down
      on all systems not absolutely needing time-of-day synchronization
      with Internet standard time servers.

      On those remaining time-sensitive systems modify the default
      configuration file (/etc/ntp.conf) to use the "restrict" clause,
      to restrict all but allow some.

      We provide an example of a simple configuration.  Please refer
      to the man (1M) xntpd for further configuration details.

        # This server syncs from server and provides
        # time services to client,  yet
        # blocks all others.

        server prefer

        # allow this client full access

        # allow this server full access

        # you need both of the following for the localhost

        # block everything else
        restrict default ignore

      NOTE:  Patches are currently in development.

   C. To subscribe to automatically receive future NEW HP Security
      Bulletins from the HP IT Resource Center via electronic mail,
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      Use your browser to get to the HP IT Resource Center page


      Under the Maintenance and Support Menu (Electronic Support
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      Under the Maintenance and Support Menu, click on the "more..."
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      To -subscribe- to future HP Security Bulletins or other
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      To -gain access- to the Security Patch Matrix, select
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      The security patch matrix is also available via anonymous ftp:


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

   D. To report new security vulnerabilities, send email to


      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

      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:  HPSBUX0104-148--------------------------------------

- --------------------------END INCLUDED TEXT--------------------

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