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-
- **************************************************************************
- Security Bulletin 9421 DISA Defense Communications System
- June 6, 1994 Published by: DDN Security Coordination Center
- (SCC@NIC.DDN.MIL) 1-(800) 365-3642
-
- DEFENSE DATA NETWORK
- SECURITY BULLETIN
-
- The DDN SECURITY BULLETIN is distributed by the DDN SCC (Security
- Coordination Center) under DISA contract as a means of communicating
- information on network and host security exposures, fixes, and concerns
- to security and management personnel at DDN facilities. Back issues may
- be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.112.36.5]
- using login="anonymous" and password="guest". The bulletin pathname is
- scc/ddn-security-yynn (where "yy" is the year the bulletin is issued
- and "nn" is a bulletin number, e.g. scc/ddn-security-9302).
- **************************************************************************
-
- + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
- ! !
- ! The following important advisory was issued by the Computer !
- ! Emergency Response Team (CERT) and is being relayed unedited !
- ! via the Defense Information Systems Agency's Security !
- ! Coordination Center distribution system as a means of !
- ! providing DDN subscribers with useful security information. !
- ! !
- + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
-
- =============================================================================
- CA-94:10 CERT Advisory
- June 3, 1994
- IBM AIX bsh Vulnerability
- -----------------------------------------------------------------------------
-
- The CERT Coordination Center has learned of a vulnerability in the
- batch queue (bsh) of IBM AIX systems running versions prior to and
- including AIX 3.2.
-
- CERT recommends disabling the batch queue by following the workaround
- instructions in Section III below. Section III also includes
- information on how to obtain fixes from IBM if the bsh queue
- functionality is required by remote systems.
-
- As we receive additional information relating to this advisory, we
- will place it, along with any clarifications, in a CA-94:10.README
- file. CERT advisories and their associated README files are available
- by anonymous FTP from info.cert.org. We encourage you to check the
- README files regularly for updates on advisories that relate to your
- site.
-
- -----------------------------------------------------------------------------
-
- I. Description
-
- The queueing system on IBM AIX includes a batch queue, "bsh",
- which is turned on by default in /etc/qconfig on all versions of
- AIX 3 and earlier.
-
- II. Impact
-
- If network printing is enabled, remote and local users can gain
- access to a privileged account.
-
- III. Solution
-
- In the next release of AIX, the bsh queue will be turned off by
- default. CERT recommends that the bsh queue be turned off using
- the workaround described in Section A below unless there is an
- explicit need to support this functionality for remote hosts. If
- this functionality must be supported, IBM provides fixes as
- outlined in Sections B and C below. For questions concerning
- these workarounds or fixes, please contact IBM at the number
- provided below.
-
- A. Workaround
-
- Disable the bsh queue by following one of the two procedures
- outlined below:
-
- 1. As root, from the command line, enter:
- # chque -qbsh -a"up = FALSE"
-
- 2. From SMIT, enter:
- - Spooler
- - Manage Local Printer Subsystem
- - Change/Show Characteristics of a Queue
- select bsh
- - Activate the Queue
- select no
-
- B. Emergency fix
-
- Obtain and install the emergency fix for the version(s) of AIX
- used at your site. Fixes for the various levels of AIX are
- available by anonymous FTP from software.watson.ibm.com. The
- files are located in /pub/aix/bshfix.tar.Z in compressed tar
- format. Installation instructions are included in the README
- file included as part of the tar file.
-
- The directory /pub/aix contains the latest available emergency
- fix for APAR IX44381. As updates become available, any new
- versions will be placed in this directory with the name
- bshfix<#>.tar.Z with <#> being incremented for each update.
- See the README.FIRST file in that directory for details.
-
- IBM may remove this emergency fix file without prior notice if
- flaws are reported. Due to the changing nature of these
- files, no checksum information is available.
-
- C. Official fix
-
- The official fix for this problem can be ordered as APAR
- IX44381.
-
- To order APARs from IBM in the U.S., call 1-800-237-5511 and
- ask that it be shipped to you as soon as it is available. To
- obtain APARs outside of the U.S., contact your local IBM
- representative.
-
- ---------------------------------------------------------------------------
- The CERT Coordination Center wishes to thank Gordon C. Galligher of
- Information Resources, Inc. for reporting this problem and IBM
- Corporation for their support in responding to this problem.
- ---------------------------------------------------------------------------
-
- If you believe that your system has been compromised, contact the CERT
- Coordination Center or your representative in Forum of Incident
- Response and Security Teams (FIRST).
-
- If you wish to send sensitive incident or vulnerability information to
- CERT via electronic mail, CERT strongly advises that the e-mail be
- encrypted. CERT can support a shared DES key, PGP (public key
- available via anonymous FTP on info.cert.org), or PEM (contact CERT
- for details).
-
- Internet E-mail: cert@cert.org
- Telephone: 412-268-7090 (24-hour hotline)
- CERT personnel answer 8:30 a.m.-5:00 p.m. EST(GMT-5)/EDT(GMT-4),
- and are on call for emergencies during other hours.
-
- CERT Coordination Center
- Software Engineering Institute
- Carnegie Mellon University
- Pittsburgh, PA 15213-3890
- USA
-
- Past advisories and their associated README files, information about FIRST
- representatives, and other information related to computer security are
- available for anonymous FTP from info.cert.org.
-
-
- ****************************************************************************
- * *
- * The point of contact for MILNET security-related incidents is the *
- * Security Coordination Center (SCC). *
- * *
- * E-mail address: SCC@NIC.DDN.MIL *
- * *
- * Telephone: 1-(800)-365-3642 *
- * *
- * NIC Help Desk personnel are available from 7:00 a.m.-7:00 p.m. EST, *
- * Monday through Friday except on federal holidays. *
- * *
- ****************************************************************************
-
- PLEASE NOTE: Many users outside of the DOD computing communities receive
- DDN Security bulletins. If you are not part of DOD community, please
- contact your agency's incident response team to report incidents. Your
- agency's team will coordinate with DOD. The Forum of Incident Response and
- Security Teams (FIRST) is a world-wide organization. A list of FIRST member
- organizations and their constituencies can be obtained by sending email to
- docserver@first.org with an empty subject line and a message body containing
- the line: send first-contacts.
-
- This document was prepared as an service to the DOD community. Neither the
- United States Government nor any of their employees, makes any warranty,
- expressed or implied, or assumes any legal liability or responsibility for
- the accuracy, completeness, or usefulness of any information, product, or
- process disclosed, or represents that its use would not infringe privately
- owned rights. Reference herein to any specific commercial products, process,
- or service by trade name, trademark manufacturer, or otherwise, does not
- necessarily constitute or imply its endorsement, recommendation, or favoring
- by the United States Government. The opinions of the authors expressed herein
- do not necessarily state or reflect those of the United States Government,
- and shall not be used for advertising or product endorsement purposes.
-