Published:
06 March 1997
Protect yourself against future threats.
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AUSCERT External Security Bulletin Redistribution
ESB-97.029 -- Digital Advisory SSRT0435U DoP
7 March 1997
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Digital Equipment Corporation has released the following advisory
concerning a vulnerability in the Division of Privilege program
/usr/sbin/dop under DIGITAL UNIX V4.0, V4.0A and V4.0. This vulnerablility
may allow local users to gain root access.
This following security bulletin is provided as a service to AUSCERT's
members. As AUSCERT did not write this document, AUSCERT has had no
control over its content. As such, the decision to use any or all of this
information is the responsibility of each user or organisation, and should
be done so in accordance with site policies and procedures.
Contact information for Digital Equipment Corporation is included in the
Security Bulletin below. If you have any questions or need further
information, please contact them directly.
If you believe that your system has been compromised, contact AUSCERT or your
representative in FIRST (Forum of Incident Response and Security Teams).
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 4477
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AUSCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for emergencies.
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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.
__________________________________________________________________
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