Division of Privilege (DoP) - Potential Security Vulnerability

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  PRODUCT:  DIGITAL UNIX[TM] V4.0, V4.0A, V4.0B         MARCH 6, 1997

  TITLE:  Division of Privilege (DoP) - Potential Security Vulnerability
  SOURCE: Digital Equipment Corporation
          Software Security Response Team/Colorado Springs USA

  "Digital is broadly distributing this Security Advisory in order to
  bring to the attention of users of Digital's products the important
  security information contained in this Advisory.  Digital recommends
  that all users determine the applicability of this information to
  their individual situations and take appropriate action.

  Digital does not warrant that this information is necessarily
  accurate or complete for all user situations and, consequently,
  Digital will not be responsible for any damages resulting from
  user's use or disregard of the information provided in this
  Advisory."

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IMPACT:

  Digital has discovered a potential vulnerability with the
  Division of Privilege (DoP), "/usr/sbin/dop" for DIGITAL UNIX
  V4.0, V4.0A and V4.0B, where under certain circumstances,
  an unauthorized user may gain unauthorized privileges.  Digital
  strongly recommends that the workaround be implemented
  immediately for any version affected, and that the
  appropriate patch kit be installed as soon as it becomes
  available.


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RESOLUTION:

  This potential security issue has been resolved and an
  official fix for this problem will be made available
  beginning the 13th of March 1997. As the patches become
  available per affected version, Digital will provide them
  through:

  o the World Wide Web at the following FTP address:

    ftp://ftp.service.digital.com/public/
        the sub directory Digital_UNIX, key identifier SSRT0435U


  Note: [1]The patch kits mentioned above will be replaced in
        the near future through normal patch release
        procedures.

        [2]The appropriate patch kit must be reinstalled
        following any upgrade beginning with V4.0
        up to and including V4.0b.


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TEMPORARY WORKAROUND:

  Prior to receiving the official patch for this fix, a
  temporary workaround for this problem is to clear the
  setuid bit from the /usr/sbin/dop command as follows:

                # chmod 0 /usr/sbin/dop

  This temporary workaround will resolve the security issue,
  but will also defeat DoP's purpose.  See "ADDITIONAL
  COMMENTS" below for the purpose of DoP, the effect of
  using this temporary workaround, and what to do as a
  solution while using this temporary workaround.

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ADDITIONAL COMMENTS:

  The DoP command is used to provide non-root users with the
  ability to enter the root password to access the graphical
  system management applications via the CDE application
  manager or the Host Manager.  When a non-root user
  attempts to execute a system management application
  through one of these applications, the user will be
  prompted with a password dialog.  If the user enters the
  correct root password, they will gain root privilege while
  running the given application.

  If the setuid bit is cleared from /usr/sbin/dop, then
  users will not be able to access the system management
  applications from either the CDE application manager or
  the Host Manager.

  The following are workarounds to allow users to run the
  graphical system management applications with DoP
  disabled:

  [1] Log into a CDE session as root and access the system
  management applications.

  [2] If logged in as a normal user, become root in your
  preferred X-based terminal emulator (xterm, dxterm, dtterm,
  etc.) and run the graphical system management application
  via the command line.

  If you need further information, please contact your
  normal DIGITAL support channel.

  DIGITAL appreciates your cooperation and patience. We
  regret any inconvenience applying this information may cause.

  __________________________________________________________________
  Copyright (c) Digital Equipment Corporation, 1995 All
  Rights Reserved.
  Unpublished Rights Reserved Under The Copyright Laws Of
  The United States.
  __________________________________________________________________